JIMOH, JELILI ADEBAYO - University of Nigeria, Nsukka · JIMOH, J. A. Dr. B. A. OGWO CANDIDATE...

COMPARATIVE EFFECTS OF TWO AND THREE

DIMENSIONAL TECHNIQUES OF AUTOCAD ON SPATIAL

ABILITY, INTEREST AND ACHIEVEMENT OF NATIONAL

DIPLOMA STUDENTS IN ENGINEERING GRAPHICS

by

JIMOH, JELILI ADEBAYO

PG/Ph.D/05/39644

DEPARTMENT OF VOCATIONAL TEACHER EDUCATION

(Industrial Technical Education)

FACULTY OF EDUCATION

UNIVERSITY OF NIGERIA, NSUKKA

MARCH, 2010

1

COMPARATIVE EFFECTS OF TWO AND THREE

DIMENSIONAL TECHNIQUES OF AUTOCAD ON SPATIAL

ABILITY, INTEREST AND ACHIEVEMENT OF NATIONAL

DIPLOMA STUDENTS IN ENGINEERING GRAPHICS

A THESIS PRESENTED TO THE DEPARTMENT OF VOCATIONAL TEACHER EDUCATION, UNIVERSITY OF

NIGERIA, NSUKKA, IN FULFILMENT OF THE REQUIREMENTS FOR THE AWARD OF DOCTOR OF PHILOSOPHY DEGREE IN

INDUSTRIAL TECHNICAL EDUCATION

by

JIMOH, JELILI ADEBAYO

PG/Ph.D/05/39644

MARCH, 2010

2

APPROVAL PAGE

THIS THESIS HAS BEEN APPROVED FOR THE DEPARTMENT OF VOCATIONAL TEACHER EDUCATION

UNIVERSITY OF NIGERIA, NSUKKA

by

----------------------------------------- ------------------------------------------- Dr. B. A. OGWO INTERNAL EXAMINER SUPERVISOR ------------------------------------------ ------------------------------------------- EXTERNAL EXAMINER Dr. E. E. AGOMUO

HEAD OF DEPARTMENT

---------------------------------------------- Prof. G. C. OFFORMA,

DEAN, FACULTY OF EDUCATION

3

CERTIFICATION

JIMOH, JELILI ADEBAYO a Postgraduate student in the Department of Vocational

Teacher Education and with Registration Number PG/Ph.D/05/39644 has satisfactorily

completed the requirements for research work for the degree of Doctor of Philosophy in

Industrial Technical Education. The work embodied in this project is original and has not

been submitted in part or full for any Diploma or Degree of this or any other University.

------------------------------------- ----------------------------------------- JIMOH, J. A. Dr. B. A. OGWO CANDIDATE SUPERVISOR

DEDICATION

This work is dedicated to Almighty God

4

and

My Parents, Mr and Mrs Jimoh, Tijani

5

ACKNOWLEDGEMENTS

First and foremost, I wish to express my profound gratitude to God, the most gracious,

the omnipotent and the omniscience for giving me the energy, courage, foresight, sound

cognition and health to start and accomplish this work. Standing on the shoulder of giants, I

would like to express my gratitude to all who have provided the support to complete this

study. I would especially like to thank my supervisor – Dr. B. A. Ogwo, for his years of

commitment and collaboration. From the beginning, he has provided an environment that

fostered intellectual growth through a mix of freedom to explore new ideas, practical research

experiences and opportunities to join the larger community of academics. I appreciate Dr.

Ogwo, for his engaging conversations through the use of virtual talk (yahoo messenger) when

he was on sabbatical leave in the United States.

I wish to extend my thanks to all the lecturers in the Department of Vocational

Teacher Education for their ceaseless assistance in transforming my dreams to reality. My

gratitude goes to Prof. S. O. Olaitan, Sir, Prof. S. C. O. A. Ezeji, Prof. J. N. Ogbazi, Prof. E.C.

Osuala, Prof. R. N. Oranu, Prof. O. M. Okoro, Prof. (Mrs) Obi, Dr. E. E. Agomuo, Dr. E. O.

Ede, and Dr. E.C. Osinem for their positive contributions towards the successful completion

of this work.

I am most grateful to Dr. K. O. Usman for his contributions, guidance, continuous

encouragement, moral and financial support that led to successful completion of the study. I

remain grateful for his limitless kindness. infact, he remains a father to reckon with. I dearly

recognise with much thanks, the wonderful contribution of Dr. (Mrs) T. C. Ogbuanya, who

remain a mother in a million. She actually supported this worthy course. It is with deep

appreciation that I thank my brother- Surveyor B. B. Ajibade for his guidance, moral and

financial support in this endeavour.

I also recognise with thanks, the contribution of Dr. C. E. Nwachukwu, and Dr. E. O.

Anaele for their sustained interest input in this study. Their contributions, direction and

encouragement actually gave focus to the study, from the study’s initial stage to its

completion. The contributions of Dr. F. A Okwo, Dr. U. Eze, Dr. J. O. S. Banjo and Dr. V.

Nwachukwu is gratefully acknowledged.

I wish to thank all my childhood friends who in various ways lent support and

encouragement to this work. Special thanks go to Mr. I. O. Mustapha, Mr. F. Amsat, Mr. Q.

B. Adeniran, Mr. B. Akeem. Mr. M. Adewuyi, Mr. A. Opaleye, Surveyor R. O. Oyekalu, and

Mr. S. O. Azeez for their words of encouragement and support that gingered me to this height.

I am particularly grateful to Mr. S. A. Salawu, Mr. T. A. O. Atanda, Mr. S. T. Oladipo,

and Mr. O. S. Edori for their assistance, moral and financial support. Thanks also go to

6

Deacon. A. A. Ayoola, Alhaji. S. Busari, and Rev. E. O. Adegoke who in various ways lent

support to this work. I am also grateful to those who facilitated this study and other research

assistants, such as Mr. K. A Yusuf and Mr. O Kosemani of Mechanical Engineering

Department, the Polytechnics, Ibadan, Mr. S. Onipede of Yaba College of Technology, Yaba,

Lagos, Mr. Odukoya Adeleke and Mr. Diabana Patrick of Mechanical Engineering

Department, Lagos State Polytechnic, Lagos . The nice company and sustaining efforts of

fellow doctoral candidates cannot be forgotten. Especially, I wish to acknowledge with thanks

the assistance received from Dr. S. Olabiyi, Mr. J. O. Owoso, Mr. R. A Dawodu, Mr. M.

Alimi, Mr. L. Lasisi Mr. B. B. Kwasu and Mr. F. Keshiro, Mr. E. E. Asuquo and Mr. A

AbdulKadir which contributed immensely to the quality of this work. Finally, my sincere

appreciation goes to my darling wife for her sacrifice, patience, endurance and support. We

pray God’s Grace to enjoy the fruits of this labour.

Jimoh, J. A University of Nigeria Nsukka

7

TABLE OF CONTENTS Page TITLE PAGE … … … … … … … … … i

APPROVAL PAGE ….. …. …. … …. …. …. …. … ii

CERTIFICATION …. …. …. …. …. …. …. …. … iii

DEDICATION …. …. …. …. …. …. …. … … iv

ACKNOWLEDGEMENTS … … … … … … … … v

TABLE OF CONTENTS … … … … … … … … vi

LIST OF TABLES … ….. … … … … … … … vii

LIST OF FIGURES … ….. … … … … … … … viii

ABSTRACT … … … … … … … … … …. x

CHAPTER I: INTRODUCTION … … … … … …. 1

Background of the Study … … … … … … …. 1

Statement of the Problem … … … … … … …. 7

Purpose of the Study … … … … … … … …. 8

Significance of the Study … … … … … … …. 9

Research Questions …. …. …. ….. …. …. ….. …. 10

Hypotheses …. …. …. …. …. …. … …. …. 11

Delimitation of the Study … … … … … …` ….. 11

CHAPTER II: REVIEW OF RELATED LITERATURE …. …. … 12

Conceptual Framework …. ….. …… ….. ….. …. ….. 12

Engineering Graphics: Meaning and its Importance to

Mechanical Engineering Students …. … …. …. …. ….. 12

AutoCAD- Ergonomics and Techniques of Graphics

in AutoCAD Environment ….. ….. …… …… …. …. …. 14

Spatial Ability and its importance to Students’ Achievement

in Engineering Graphics …. …. ….. …… ….. …. ….. 24

Improving Students Spatial Ability in Engineering Graphics

with CAD Packages ….. ….. …. ….. …. ….. ….. ….. 31

Relationship between Gender and Spatial Ability ….. ….. …. ….. 34

Improving Students’ Interest in the Study of Engineering

Graphics with Computer Technology ….. ….. …… …… …. ….. 36

Computer Technology use in Teaching and Students’ Achievement …. 39

8

Theoretical Frame Work …. ….. ….. ….. ….. ……. …. 40

Jerome Bruner’s Theory and the Use of AutoCAD for Improving

Student’s Interest and Achievement in Engineering Graphics ….. … ….. 40

Ausbel’s Subsumption Theory of Learning and the Use of AutoCAD

for Improving Students’ Achievement in Engineering Graphics …. ….. 42

Cognitive Interaction Learning Theory and Development

of spatial Ability …. …. …. …. …. …. ….. 43

Piaget’s Theory of Cognitive Development and Spatial Ability

Development ….. ….. ….. …. …. …. …. …. ….. 44

Need Achievement Theory of Motivation and Use of Computer

Technology for Stimulating Students’ Interest in Learning …. …. …. 47

Review of Related Empirical Studies ….… …. …… …. …. 48

Summary of the Reviewed Related Literature ….. …. …. …. 57

CHAPTER III: METHODOLOGY … … … … … …. 59

Research Design … … … … … … … … …. 59

Area of the Study … … … … … … … …. 59

Population … … … … … … … … …. 60

Sample and Sampling Technique …. ….. …. …. ….. …. 60

Instruments for Data Collection … … … … … …. 61

Validation of the Instruments…. … … … … … …. 61

Reliability of the Instruments … … … … … … …. 62

Control of Extraneous Variables … ….. ….. ….. …. …. 63

Experimental Procedure ….. ….. ….. ….. …. ….. ….. 64

Method of Data Collection … … … … … … …. 67

Method of Data Analysis …. ….. …. ….. ….. …. ….. 68

CHAPTER IV: PRESENTATION AND ANALYSIS OF DATA …. …. 69 Research

Question 1… … … … … … … …. 69

Research Question 2… … … … … … … …. 69





9

Hypothesis 1… … … … … … … … …. 73

Hypothesis 2… … … … … … … … …. 73

Hypothesis 3… … … … … … … … …. 73

Hypothesis 4…. …. …. …. …. …. …. … …. 74

Hypothesis 5…. ….. …. ….. ….. ….. ….. ….. …. 74

Hypothesis 6….. …. ….. …. …. …. …. …. …. 75

Hypothesis 7….. ….. ….. …… ….. ….. ….. …. ….. 75

Hypothesis 8….. …. ….. …… ….. ……. …… …. …. 75

Hypothesis 9…. …. …. …. …. …. …. … …. 76

Findings of the Study…. …. … … … … … …. 77

Discussion of the Findings… … … … … …. … ….. 78

CHAPTER V: SUMMARY, CONCLUSIONS AND RECOMMENDATIONS… 83

Re-Statement of the Problem… … … … … … …. 83

Summary of the Procedures Used… … … … … … …. 84

Principal Findings… … … … … … … … …. 86

Conclusion… … … … … … … … … …. 86

Implication of the Study… … … … … … … …. 87

Recommendations… … … … … … … … …. 88

Suggestions for Further Studies… … …. … … … …. 89

REFERENCES... … … … … … … … … …. 90 APPENDICES APPENDIX A:- AutoCAD Techniques, Actual Treatments

to the Students and the Dependent Variables Covered …. 102 APPENDIX B:- Sample of AutoCAD 3-D Lesson Plans …. .… …. 107

APPENDIX C:- Sample of AutoCAD 2-D Lesson Plans …. …. …. 220

APPENDIX D:- Population Distribution of Students according to Institutions …. ….. …. …. ….. … 302

APPENDIX E:- Training Plans for Teachers and Students…. ….. … 303 APPENDIX F:- Summary of the Difficulty, Discrimination

and Distractor Indices of Engineering Graphics Achievement Test….. ….. ….. ….. …. …. 306

APPENDIX G:- Result of Factor Analysis for the Engineering Graphics Interest Inventory….. ….. …... … …. 308

APPENDIX H:- Reliability Coefficient for Purdue Visualization of Rotations Test, Engineering Graphics Achievement Test and Engineering Graphics Interest Inventory.. … 310

APPENDIX I:- Engineering Graphics Achievement Test. …. … …. 312

APPENDIX J:- Engineering Graphics Interest Inventory ….. ….. 333

10

APPENDIX K:- Purdue Visualization of Rotations Test…. ….. … ….. 335

List of Tables Table

Page

1 Mean of Pretest and Posttest of Treatment Groups taught Engineering Graphics with AutoCAD techniques (2-D and 3-D) in the Engineering Graphics Achievement Test

69

2 Mean of Pretest and Posttest of Treatment Groups taught Engineering Graphics with AutoCAD techniques (2-D and 3-D) in the Purdue Visualization of Rotations Test (PVRT)

70

3

Mean of Pretest and Posttest of Treatment Groups taught Engineering Graphics with AutoCAD techniques (2-D and 3-D) in the Engineering Graphics Interest Inventory

70

4 Mean of Pretest and Posttest of Male and Female students taught Engineering Graphics with AutoCAD techniques (2-D and 3-D) in the Purdue Visualization of Rotations Test (PVRT)

71

5 Mean of Pretest and Posttest of Male and Female students taught Engineering Graphics with AutoCAD techniques (2-D and 3-D) in the Engineering Graphics Achievement Test

72

6 Mean of Pretest and Posttest of Male and Female students taught Engineering Graphics with AutoCAD techniques (2-D and 3-D) in the Engineering Graphics Interest Inventory

73

7

Summary of Analysis of Covariance (ANCOVA) for Test of Significance of Main Effects Of Treatment and Gender and Interaction Effects of Treatments given to Students Taught with AutoCAD and their Gender with Respect to their Mean Scores on Engineering Graphics Achievement Test

74

8

Summary of Analysis of Covariance (ANCOVA) for Test of Significance of Main Effects of Treatment and Gender and Interaction Effects of Treatments Given to Students Taught With AutoCAD and their Gender with Respect to their Mean Scores on Purdue Visualization of Rotations Test

75

9

Summary of Analysis of Covariance (ANCOVA) for Test of Significance of Main Effects of Treatment and Gender and Interaction Effects of Treatments Given to Students Taught with AutoCAD and their Gender with Respect to their Mean Scores on Engineering Graphics Interest Inventory

76

11

List of Figures

Figures

Page

1 AutoCAD in its default display 15 2

The UCS icon in its default display

16

3

World Coordinate System with three axes (X, Y and Z) at an angle of 900 to each other

17

4

The UCS at 3-D Isometric

17

5

Two-Dimensional coordinate system

19

6

Rectangle constructed with absolute coordinate of 2-D coordinate system

19

7

Rectangle constructed with relative coordinate of 2-D coordinate system

20

8 AutoCAD Isometric mode showing an Isometric cube and the crosshair representing X- and Y- axes

21

9 Isometric object constructed with absolute and polar coordinate of 2-D coordinate system

21

10 Three-Dimensional coordinate system 22

11

Rectangle constructed with absolute coordinate of 3-D coordinate technique

22

12

Rectangle drawn with relative coordinate of 3-D coordinate technique

23

13 Line drawn with cylindrical coordinate 23

14 line drawn with Spherical coordinate system

24

15 Isometric object constructed with 3-D coordinate system in a 3-D South East isometric

24

16 Interaction between the learner and the computer environment for 44

12

developing spatial ability

Abstract This study was designed to determine comparative effects of two and three dimensional techniques of AutoCAD on National Diploma students’ spatial ability, interest and achievement in engineering graphics. The study was a pretest, posttest, non-equivalent control group quasi-experiment which involved groups of students in their intact classes assigned to treatment groups. Six research questions and nine hypotheses, tested at 0.05 level of significance, guided the study. The population of the study consisted of 350 ND I mechanical engineering technology students in the polytechnics in the south-western geo-political zone of Nigeria. The sample size was 227 students from which 108 students constituted treatment groups assigned to AutoCAD 2-D technique, and 119 students constituted another treatment groups assigned to AutoCAD 3-D technique. The instruments used for data collection were Purdue Visualization of Rotation Test (PVRT), Engineering Graphics Achievement Test (EGAT), and Engineering Graphics Interest Inventory. The Purdue Visualization of Rotation Test (PVRT) was adopted and had been validated by the test developer. To ensure content validity of the EGAT, a Table of Specification was built for the test. The PVRT, EGAT, Engineering Graphics Interest Inventory, the AutoCAD 2-D and 3-D lesson plan and the Training plans for the engineering graphics lecturers and students were subjected to face validation by five Experts. The EGAT was trial tested for the purpose of determining the psychometric indices of the test. A total of 45 items of the EGAT had good difficulty, discrimination and distractor indices. In addition to face validation, the engineering graphics Interest Inventory was also subjected to construct validation using factor analysis technique. Out of 40 items, a total of 28 items were finally selected for the interest inventory. The reliability coefficient of the PVRT had been established by the test developer. However, to account for varied cultural and social context, a trial test was carried out on the PVRT for determining its reliability coefficient. Split Half reliability was computed to be .82 for samples of 39. The trial test for determining the coefficient of stability of the EGAT was carried out using test re-test reliability technique. Pearson Product Moment Correlation coefficient of the EGAT was found to be .80. Cronbach Alpha was used to determine the internal consistency of the Engineering Graphics Interest Inventory items. The reliability coefficient computed for the Engineering Graphics Interest inventory was found to be .91. The data collected were analyzed using Mean, to answer the research questions while ANCOVA was used to test the nine hypotheses formulated to guide this study. The study found out that AutoCAD 3-D technique is more effective in improving students’ achievement, spatial ability and interest in engineering graphics than AutoCAD 2-D technique. There was a significant effect of Gender on students’ spatial ability and achievement in engineering graphics favouring boys. The study found out no significant interaction effects of AutoCAD techniques and gender on spatial ability, achievement and interest of National Diploma students in engineering graphics. Hence, irrespective of nature of gender, learners will record improved performance in their spatial ability, interest and achievement in engineering graphics when AutoCAD 3-D technique is employed for teaching engineering graphics. Consequently, it was recommended that (1). Technical teachers teaching engineering graphics should adopt the use of AutoCAD

13

3-D technique to teach engineering graphics; and prepare their lessons in such a way that students are allowed ample opportunity to interact freely with virtual objects and animation in the AutoCAD 3-D space. (2). National Board for Technical Education (NBTE) should consider review of curriculum for Engineering Graphics with a view to incorporating AutoCAD 3-D technique into the teaching of engineering graphics. (3). Workshops, seminars and conferences should be organized by Ministry of Education and administrators of polytechnics to enlighten technical teachers and improve their knowledge and skills on the use of AutoCAD 3-D techniques for improving students’ achievement, interest and spatial ability in engineering graphics.

14

CHAPTER I

INTRODUCTION

Background of the Study

Computer-Aided Design (CAD) denotes the integrated use of computer in the

conceptualization and design of products. According to Christopher (1990) Computer-Aided

Design embraces the use of computer in the industry for design, simulation and graphics

design such as engineering graphics. Engineering graphics is one of the core courses for

students of National Diploma in Mechanical Engineering Technology in the Nigeria

Polytechnics. It involves construction of different geometric figures and shapes, orthographic

projections, orientation of objects in space, developments of objects and intersections of

regular solids and planes (National Board for Technical Education (NBTE), 2003). Spatial

visualization is an established element of engineering graphics and is integral for success in

graphics and engineering as a whole (Strong and Smith, 2002). Recent attention to spatial

ability in engineering graphics, according to Basham (2007), is largely due to the vast changes

in computer technology and CAD software packages. Many application software packages

have been developed for computer-aided design, well-known among the CAD packages

available for graphics design is AutoCAD.

AutoCAD is an interactive drafting software package developed for construction of

objects on a graphics display screen. It is a vector graphics software developed in 1982 by

Autodesk incorporation (Bui, 2006). It uses primitive entities such as lines, polylines, circles,

arcs and text as the foundation for more complex objects (Wikipedia, 2007). According to

Bui, AutoCAD is one of the most powerful CAD software which can perform nearly any

graphics task. There are two techniques of graphics in AutoCAD environment. These

techniques of graphics are the two-dimensional (2-D) and the three-dimensional Cartesian

coordinate systems for locating the positions of geometric forms in AutoCAD 2-D and 3-D

space respectively. Specifically, AutoCAD two-dimensional technique involves the use of

two-dimensional Cartesian coordinates system for graphics construction in AutoCAD

environment. It entails specifying coordinate with the X and Y Cartesian coordinate system

only. Whereas, AutoCAD three-dimensional technique involves the use of three-dimensional

Cartesian coordinates system for graphics construction in AutoCAD environment. This has to

do with specifying coordinates with X, Y, and Z Cartesian coordinate system (Bertoline and

Wiebe, 2005; Finkelstein, 2002). With these two techniques of graphics in AutoCAD, users of

AutoCAD have option of using any of the two techniques for graphics construction.

Over the years, since the existence of 2-D CAD packages, there has been a wide

acceptance of CAD software packages in education community as a learning tool for

1

15

geometry construction and other graphics designs in various disciplines. This is because CAD

software has command prompt which provides human and computer interface that enhance

students’ interaction with the learning environment. Planned students’ interactions with

learning environment are the most critical components of any learning environment,

particularly, computer-based learning and are known to have a positive effect in students’

learning, engage students in the learning tasks, thereby help sustain students’ interest in

learning and consequently improve students’ achievement and construction of knowledge

(Osberg, Winn, Rose, Hollander, Hoffman and Char, 1997). Besides, the computer

technology, when used as a learning tool, the teacher interacts very differently with the

students more as a guide, model and mentor (Basu, 1997). AutoCAD provides users with

command prompts which users must read and respond as needed (Omura, 2003; Alice, 2001).

Students’ interaction with AutoCAD command according to Lemut, Pedemonte and Robotti

(2000) provides human and computer interface which has a direct relationship to students’

cognitive ability and a tendency to improve students’ construction of knowledge and transfer

of learning. Lemut, et al explained that under the teacher’s guidance, construction of objects

in AutoCAD favour a deep understanding of the meaning of geometric construction, in that,

during construction process, students have to think about the definitions, properties of the

geometric figures and geometric relationships because construction strategies in AutoCAD are

not free as in the pen-and–paper environment but are guided by the system’s request

appearing on the command prompt.

Furthermore, one aspect of AutoCAD and many other CAD programs is that

geometric construction relies heavily on the understanding of the Cartesian Systems (2-D and

3-D) and the ability to relate it to the objects in space. The 2-D and 3-D Cartesian coordinate

systems, commonly used in mathematics and graphics, locate the positions of geometric forms

in 2-D and 3-D space respectively. This system was first introduced in 1637 by a French

Mathematician, Rene Descartes. The coordinate geometry based on these systems theorize

that for every point in space, a set of real numbers can be assigned, and for each set of real

numbers, there is a unique point in space (Bertoline and Wiebe, 2005). Construction of

geometric figures with the Cartesian systems provides learning environment that facilitates

better understanding of spatial properties and relationship of objects and space (Rafi,

Samsudin and Said, 2008). According to Hegarty and Waller (2005) the use of coordinate

systems for locating points in 2-D or 3-D space when specifying dimensions of geometry

figures in CAD packages improves students cognitive abilities associated with visual imagery,

as well as the ability to perceive number, space configurations and processing of spatial

information.

16

In addition, before the advent of Release 10 version of AutoCAD, it was a fully self-

contained two-dimensional CAD software. The advent of Release 10 capable of 3-D

coordinate system marked a remarkable turning point in AutoCAD techniques and

applications (Texas Academic and Management Consult, 2000). With this development,

AutoCAD software package now has both two-dimensional and three-dimensional techniques

of graphics and capable of applications such as animation, solid modeling and virtual reality.

According to Strong and Smith (2002) the impact of high performance rendering and

animation software, solid modeling packages, virtual reality, and online testing opens a

number of doors for spatial visualization research and measurement. Virtual reality is the

name of the interactive computer technology that attempts to create a completely convincing

illusion of being immersed in an artificial world which exists only inside a computer (Kamara,

2006). According to Osberg (1995) virtual reality is a superior environment for spatial skills

enhancement specifically because the interface preserves Visio-spatial characteristics of the

simulated world. Solid modeling is a three-dimensional computer generated model of an

object (Koch, 2006). Basham (2007) contended that viewing three-dimensional solid models

removes it from its usual two-dimensional form of abstraction and makes it more suitable for

use as a method for spatial visual learning. Animation on the other hand is a series of rapidly

changing computer screen displays presenting a geometrical shape and varying positions

giving the impression of movement (Mayton, 1991). Hays (1996) maintained that animated

visuals provide students’ interaction with virtual objects, allow better retention in students

learning and communicate ideas involving space better than static visuals. Besides, the

frequency with which student interacts with an animated computer model made significant

contributions to performance on a spatial visualization tasks (Love, 2004). Moreover, Hart

(2003) noted that viewer controlled animation leads to improvement in cognitive, perceptual

and motor skills, assist in anchoring the students into reality for the use of visual objects in

which spatial ability can be improved.

The word Spatial means of relating to, involving, or having the nature of space (Isaac

and Marks, 1994). Spatial ability is the intellectual ability primarily used to function and

operate in 2- or 3- dimensional spaces (Bannatyne, 2003). It is a cognitive function that makes

it possible for human being to deal effectively with spatial relations, visual-spatial tasks and

orientation of objects in space (Sjolinder, 1998). Basham (2007) refers to spatial ability as one

of the human intelligences used to formulate mental images and manipulate the images in the

mind. Within this context, spatial ability can be defined as the ability to think in picture, to

create mental images and to transform visual or spatial ideas into imaginative and expressive

17

creation. There are different categories of spatial ability. These are mental rotation, spatial

visualization, perception, orientation and imagery.

Mental rotation is the ability to mentally rotate a stimulus object in the mind in order

to envision it from different angles (Zacks, Mires, Tversky, and Hazeltine, 2000). Koch

(2006) defined spatial visualization as the ability to mentally rotate in space two-and three-

dimensional objects with one or more movable parts. The term imagery is associated with

visualization. Two types of imagery are kinetic and transformational. Basham (2007)

explained that kinetic imagery is based on one’s experience of an object’s movement which

allows an individual to judge whether an approaching object is likely to hit its target while

transformational imagery allows the mental view of an object as it changes shape or form.

This requires mental manipulation of a visual image from a different perspective such as

imagining the shape change of an object which has moved (Potter and Van der Merwe, 2001).

The spatial perception category of spatial ability relates to how individual perceives space

(Lahav, 2006). The extent of an individual’s spatial perception according to Maier (2005)

depends on spatial perceptual skills which comprise among others the ability to recognize

object and orientate oneself in the environment, transfer three-dimensional space into two-

dimensional forms, recognize depth and distance/proximity, identify and understand

relationships of location, position, scale and size. Spatial orientation refers to the ability to

recognize the identity of an object when it is seen from different angles (Tremblay, 2004).

Spatial ability is fundamental to human functioning in the physical world. Spatial

reasoning enables an individual to use concept of shapes, features and relationship in both

concrete and abstract ways, to make and use things in the world, to navigate, visualize and to

communicate (Newcomer, Raudebaugh, McKell and Kelly, 1999). In a similar way this

ability is used to envision new things and establish relationship of concepts in the mind (Jones

and Bills, 1998). Basham (2007) noted that spatial ability is basic to higher level activities

such as mathematical thinking and used for processing information presented in such

representation as maps, graphs, diagrams and other spatial layout. According to Olkun (2003)

spatial thinking is used to represent and manipulate information in learning and problem

solving in engineering, design, physics and mathematics

One of the widely publicized aspects of spatial ability is the apparent differences

between genders. Gender, refers to a psychological term, which describes behaviours and

attributes expected of individual on the basis of being a male or a female (Uwameiye and

Osunde, 2005). Several studies (Nemeth and Hoffmann (2006), Burin, Delgado and Prieto

(2000), and Medina, Gerson and Sorby (2000)) conducted on gender differences in spatial

ability have shown measurable differences in spatial ability of boys and girls. Generally, most

18

of the studies found out that boys have better spatial ability than girls. However, Branoff

(1998) pointed out that females could benefit as well as males from spatial training programs.

Besides, research findings by Keller and Hart (2002), Kaufmann, Steinbugl, Dunser and

Gluck (2005) and Baldwin and Hall-Wallance (2001) have indicated that spatial ability can be

improved in both children and adult. A potential benefit of improving spatial ability is the

improvement of students’ achievement in areas of mathematics, engineering and sciences

(Mohler, 2006; Baldwin and Hall-Wallance, 2001).

Students’ achievement connotes performance in school subject as symbolized by a

score or mark on an achievement test. According to Anene (2005) achievement is quantified

by a measure of the student’s academic standing in relation to those of other students of his

age. Atherson (2003) and Uka (1981) contended that students’ achievement is dependent

upon several factors among which are instructional methods and learning environment.

Teachers with a demanding but good teaching method challenge students to work at higher

intellectual level. Presently, demonstration using drawing instruments on chalk board is

predominantly used to teach engineering graphics to the National Diploma students in the

polytechnics. Demonstration is any planned performance by a vocational/technical teacher on

an occupational skill/information aimed at explaining the steps/facts of an operation (Ogwo

and Oranu, 2006). The method is executed by example and activities by the teacher while the

learners observe and listen (Ukoha and Eneogwe, 1996).

Besides the use of good teaching method in the classroom, another important role of

the teacher is to order and structure the learning environment. Included in this role are all the

decision and action required of the teacher to maintain order in the classroom such as laying

down rules and procedures for learning and use of motivational techniques to secure and

sustain the attention and interest of the learner (Moore, 1998). Interest is a persisting tendency

to pay attention and enjoy some activities. Interest has been viewed as emotionally oriented

behavioural trait which determines a student’s vim and vigour in tackling educational

programmes or other activities (Chukwu, 2002). Students’ interest and achievement in any

learning activity is sustained by the active involvement of the learner in all aspect of the

learning process. Ogwo and Oranu (2006) and Ngwoke (2004) emphasized that unless the

teacher stimulates students’ interest in learning, students’ achievement will be minimal.

Hence, it is essential that technical teachers use teaching method which ensures students’

active involvement in learning and provide suitable learning environment to improve

achievement and stimulate interest of National Diploma (ND) students in mechanical

engineering technology to learn engineering graphics.

19

National Diploma in mechanical engineering technology is a technician diploma

certificate obtained in the polytechnics after a two years post-secondary training in

mechanical engineering technology. The diplomate according to NBTE (2003) should among

others be able to interpret and prepare engineering drawings of mechanical equipment, their

components and systems, carry out machining and fabrication operations, produce machine

components and assemble, operate, maintain and service mechanical equipment.

Engineers/technicians communicate with one another largely by graphics. In order for

technicians to be able to prepare and interpret engineering drawing of mechanical equipment

in mechanical design, the technician must be able to visualize how all the components in the

system work (Medina, Gerson and Sorby, 2000). The development of spatial ability required

for visualization is one of the main purposes of engineering graphics education (Sueoka,

Shimizu and Yokosawa, 2001)

The increasing effects of globalization and the rapid rate of technological changes on

work places have informed the recommendation by United Nations, Educational, Scientific

and Cultural Organization (UNESCO) and International Labour Organization (ILO) (2002)

that all technical and vocational education system in the 21st century should be geared towards

life long learning. This requires that schools should in addition to academic skills; inculcate

workplace basic skills such as learning to learn, creativity, problem solving skills,

collaborative skills and higher order thinking skills in order to increase the students’ flexibility

and job mobility which will make them adaptable to the present and envisaged changes

(Hallak and Poisson, 2000; Paris, 1998). In this context, Rojewskin (2002) noted that a shift

from teacher-centred instruction to learner-centred instruction is needed to enable students

acquire the new 21st century knowledge and skills. Computer technology provides powerful

tools to support the shift to student-centred learning and is capable of creating a more

interactive and engaging learning environment for teachers and learners (UNESCO, 2002).

Moreover, with the use of CAD packages, industry will like to employ graduating

engineering students who can move data throughout the design process, collaborate online

with customers, suppliers and co-workers, identify and fix problems with 3-D geometry, use

powerful knowledge-based systems to design complex assemblies, and be flexible enough to

do design and development work with CAD packages (Branoff, 2005). According to Condoor

(2007) this situation requires radical change of teaching method of engineering graphics to the

use of CAD packages. Hence, with the rapid development of technologies which has

occasioned use of CAD packages in the industry in recent years, the need to find the best

method of CAD that will assist students in mechanical engineering technology to learn

engineering graphics effectively and improve their spatial ability has become most important

20

to educators. AutoCAD which is one of the most powerful CAD software used in the industry

offers two different techniques (2-D and 3-D) of graphics. This study is therefore designed to

determine comparative effects of two and three dimensional techniques of AutoCAD on

National Diploma students’ spatial ability, interest and achievement in engineering graphics to

identify which of the techniques will be most effective to teach engineering graphics.

Statement of the Problem

The language of engineering graphics design in the industry nowadays is Computer-

Aided Design (CAD) using AutoCAD as one of the most powerful CAD software packages

which is capable of two- and three-dimensional coordinate system for graphics design.

However, demonstration with drawing instrument on the chalkboard is predominantly used by

the teachers to teach engineering graphics to National Diploma students in the polytechnics.

Apart from the fact that demonstration method is teacher-centred, it does not provide students

with learning environment that facilitates better understanding of spatial properties and

relationship of objects and space. Another major limitations of demonstration method with

drawing instruments on the chalkboard for teaching graphics is the problem of presenting

three-dimensional (3-D) spatial information in a two-dimensional format (2-D) (Mackenzie

and Jansen, 2005). Accordingly, many students taught graphics with the method have

difficulty in comprehending the graphics representation of three-dimensional objects (Scribner

and Anderson, 2005). Supporting this view, Koch (2006) noted that the difficulty is due to

lack of development of spatial skills in the students.

Technology, the world over is dynamic. With the interaction of globalization and

technological development, work organizations are getting increasingly flexible, process-

based and multi-tasking. This apparently is to suit demands of the prevalent knowledge

society and ample use of information communication technology in work places and changes

in the organization of work (Ogwo and Oranu, 2006; International Labour Organization,

(ILO), 2003). In this context, there is need for education institutions to adjust to changes in

work places so as to produce students with work place basic skills required to thrive in the 21st

century knowledge-based economy and society (Rojewskin, 2002; Qureshi, 1997). According

to UNESCO (2002) the adjustment requires the educational institutions to embrace new

technology and appropriate computer technology as a learning tool to transform the present

isolated, teacher-centred and text bound classroom into rich, students-centred interactive

knowledge environment. Furthermore, 2-D and 3-D spatial visualization and reasoning which

are core skills for engineering graphics ought to be emphasized in the teaching of engineering

21

graphics with the use of CAD packages because the development of spatial visualization skills

is one of the main purposes of engineering graphics.

However, the use of demonstration with drawing instruments on the chalkboard

apparently, results into neglect in the development of students’ spatial ability which invariably

leads to deprivation of students in everyday applications, such as translating 2-D objects to 3-

D objects, poor at estimating sizes and poor at visualizing things and relationships to one

another (Koch, 2006). Consequently, this situation leads to students’ poor academic

achievement due to inadequate learning environment for developing the spatial ability

essential in engineering graphics and sustain students’ interest in learning. Moreover, students

taught using demonstration method with drawing instruments on the chalk board will

obviously lack engineering graphics design skills required for work in the industry due to

ample use of CAD packages. It becomes pertinent to teach engineering graphics of National

Diploma students with AutoCAD which is used in the industry due to its wide range of

application capabilities and techniques. AutoCAD has two techniques of drawing. As already

established, when drawing with 3-D techniques in AutoCAD environment user no longer

deals with only x and y coordinates, but also with the z axis as well. Also, AutoCAD 3-D

permits animated visual images while AutoCAD 2-D permits static visuals. Thus, drawing

with 2-D techniques is different from drawing with 3-D technique. These differences perhaps,

may produce different effects on students’ achievement, interest and spatial ability in learning

engineering graphics. Besides, there is dearth of empirical data on the effectiveness of

AutoCAD (2-D and 3-D) techniques on the spatial ability, interest and achievement of

students in engineering graphics which could serve as a directive to professional technical

teachers and other educators. Hence, what is the comparative effect of AutoCAD (2-D and 3-

D techniques) on National Diploma Students’ spatial ability, interest and achievement in

engineering graphics?

Purpose of the Study

The major purpose of this study is to determine comparative effects of two and three

dimensional techniques of AutoCAD on spatial ability, interest, and achievement of National

Diploma students in engineering graphics. Specifically, the study sought to determine the

effect of:

1. AutoCAD techniques (2-D, and 3-D) on students’ achievement in Engineering

Graphics.

2. Using AutoCAD techniques (2-D, and 3-D) in teaching Engineering Graphics on

students’ spatial ability measured by Purdue Visualization of Rotations Test (PVRT).

22

3. AutoCAD techniques (2-D, and 3-D) on students’ interest in studying Engineering

Graphics.

4. Gender on the spatial ability test scores of students (male and female) taught

Engineering Graphics with AutoCAD techniques.

5. Gender on the achievement of students (male and female) taught Engineering Graphics

with AutoCAD techniques.

6. Gender on the interest of students (male and female) taught Engineering Graphics with

AutoCAD techniques.

Significance of the Study

The findings of this study will be of immense benefit to technical teachers teaching

engineering graphics in the polytechnics. The effect of AutoCAD (2-D and 3-D) techniques

on students’ achievement in engineering graphics identified by this study will enlighten the

teachers on the AutoCAD techniques that will improve students’ achievement in engineering

graphics. Such knowledge will help the teachers to improve their instructional delivery by

using appropriate techniques of AutoCAD for teaching polytechnics students engineering

graphics to acquire work place skills. This in effect, will result in the training of competent

mechanical engineering technicians for nation’s industrial and technological development.

Furthermore, the effect of using AutoCAD (2-D and 3-D) techniques in teaching

engineering graphics on students’ spatial ability identified by this study are expected to

provide the teachers with knowledge of AutoCAD techniques that improve students’ spatial

ability in engineering graphics. The knowledge provided will help the teachers in their

instructional design and delivery with AutoCAD techniques to improve students’ spatial

ability which is essential in engineering graphics and engineering program as a whole.

Moreover, through training in spatial skills development, students will be able to learn

engineering graphics and other technical graphics with greater efficacy as they would have

attained the proper and efficient strategy in solving engineering graphics tasks or problem that

are spatial in nature.

In addition, the effect of gender on spatial ability, achievement and interest of students

taught engineering graphics with AutoCAD techniques identified by this study will also be of

benefit to technical teachers. The finding will hopefully enable the teachers to be aware of

gender effect on spatial ability, interest and achievement of students taught engineering

graphics with AutoCAD techniques. The knowledge will help the teachers to improve their

instructional delivery by using appropriate techniques of AutoCAD to bridge the gap between

spatial ability, achievement and interest of boys and girls in engineering graphics.

23

Furthermore, the findings on effect of AutoCAD (2-D and 3-D) techniques use on students’

interest in studying engineering graphics is expected to provide the technical teachers with

information on the effectiveness of AutoCAD (2-D and 3-D) techniques on students’ interest.

The knowledge will assist the teachers on the use of AutoCAD as a learning tool for

transforming the present isolated, teacher-centred and text bound classroom into rich,

students-centred interactive knowledge environment to secure and sustain the attention of the

students in learning engineering graphics. Therefore, students will benefit from the findings of

the study. When teachers use appropriate techniques of AutoCAD to teach engineering

graphics, it is expected that the teachers will be able to create learning environment that will

ensure active students’ participation in the classroom activities to improve students’

achievement and interest in learning.

The findings of this study will also be useful to educational systems around the world

that are under increasing pressure to use the new information communication technologies

(ICTs) to teach students the knowledge and skills they need in the 21st century. Presently,

there is dearth of empirical data on the effectiveness of AutoCAD (2-D and 3-D) techniques

on the spatial ability, interest and achievement of students in graphics courses. This study will

provide empirical evidence which could serve as a directive to professional technical teachers

and other educators in their search for effectiveness of AutoCAD (2-D and 3-D) techniques in

the teaching of engineering graphics.

Finally, curriculum planners will benefit from the findings of this study. The findings

will provide empirical evidence for curriculum planners on the effectiveness of AutoCAD

techniques in the teaching of engineering graphics and other technical graphics. The

information will hopefully influence future trend in engineering and technical education

curriculum development.

Research Questions

The following are the research questions formulated for this study:

1. What is the effect of AutoCAD techniques (2-D and 3-D) on students’

achievement in Engineering Graphics?

2. What is the effect of using AutoCAD (2-D and 3-D) in teaching Engineering

Graphics on students’ spatial ability measured by Purdue Visualization of

Rotations Test (PVRT)?

3. What is the effect of using AutoCAD (2-D and 3-D) in teaching on students’

interest in studying Engineering Graphics?

24

4. What is the effect of Gender on the spatial ability test scores of students (male and

female) when taught Engineering Graphics with AutoCAD techniques?

5. What is the effect of Gender on the achievement of students (male and female)

when taught Engineering Graphics with AutoCAD techniques?

6. What is the effect of Gender on the interest of students (male and female) when

taught Engineering Graphics with AutoCAD techniques?

Hypotheses

The following null hypotheses tested at .05 level of significance guided this study:

HO1: There will be no significant mean difference between the effect of treatments

(AutoCAD 2-D and 3-D techniques) on students’ achievement in Engineering

Graphics

HO2: There will be no significant mean difference between the effect of gender (male and

female) on students’ achievement in Engineering Graphics

HO3: There will be no significant interaction effect of treatments given to students taught

with AutoCAD and their gender with respect to their mean scores on Engineering

Graphics Achievement Test


(AutoCAD 2-D and 3-D techniques) on students’ spatial ability in Engineering

Graphics


female) on students’ spatial ability in Engineering Graphics


with AutoCAD and their gender with respect to their mean scores on the Purdue

Visualization of Rotations Test


(AutoCAD 2-D and 3-D techniques) on students’ interest in Engineering Graphics


female) on students’ interest in Engineering Graphics



Graphics Interest Inventory.

Delimitation of the Study

This study is delimited to two and three dimensional techniques of AutoCAD which

are basically used for drawing engineering graphics. Thus, excluding AutoCAD programming

with Auto LIPS, Visual LIPS and Visual Basic for Application.

25

CHAPTER II

REVIEW OF RELATED LITERATURE

The review of related literature to this study is organized under the following sub-

headings:

Conceptual Framework

• Engineering Graphics: Meaning and its Importance to Mechanical Engineering Students

• AutoCAD - Ergonomics and techniques of Graphics in AutoCAD environment

• Spatial Ability and its importance to Students’ Achievement in Engineering Graphics

• Improving Students’ Spatial Ability in Engineering Graphics with the Use of Computer-

Aided Design Packages

• Relationship between Gender and spatial ability

• Improving Students’ Interest in the Study of Engineering Graphics with Computer

Technology

• Computer Technology use for Teaching and Students’ Achievement

Theoretical Framework

• Jerome Bruner’s Theory and the Use of AutoCAD for Improving Student’s Interest and

Achievement in Engineering Graphics

• Ausbel’s Subsumption Theory of Learning and the Use of AutoCAD for Improving

Students’ Achievement in Engineering Graphics

• Cognitive Interaction Learning theory and Development of Spatial Ability

• Piaget's Theory of Cognitive Development and Spatial Ability Development

• Need Achievement Theory of Motivation and the Use of Computer Technology for

Stimulating Students’ Interest in Learning

Review of Related Empirical Studies

• Studies on the Effects of Computer-Aided Design (CAD) Packages on students’ spatial

Ability and Achievement

• Studies on Effects of Gender and Spatial Ability

Summary of Reviewed Related Literature

Conceptual Framework:

Engineering Graphics: Meaning and its Importance to Mechanical Engineering Students

Mechanical Engineering technology is one of the programmes offered in the Nigeria

polytechnics. According to Okorie (2000) polytechnics is a post-secondary institution which

is designed to produce various technologist/technicians that are crucial to the economy and

12

26

developments of the country. Okorie explained further that polytechnics produce mainly

middle level technical workforce for the various sector of the economy. National Board for

Technical Education (NBTE) (2003) noted that mechanical engineering programme in the

polytechnics is designed to reflect a functional philosophy of education. NBTE explained

further that while seeking to achieve academic excellence, and promote the furtherance of

knowledge, the mechanical engineering programme also seeks to aid “¼ the acquisition of

appropriate skills, abilities and competence, both mental and physical as equipment for the

individual to live in and contribute to the development of his society.” The programme is

therefore committed to the production of qualified and competent technicians who will be able

to face the challenges concomitant with the aspiration of the country to be technological

developed and the technicians to be self-reliant after graduation.

The National Diploma students in mechanical engineering having completed their

programme should be able to interpret and prepare engineering drawings of mechanical

equipment, their components and systems; carry out machining and fabrication operations;

produce machine components and assemble; operate, maintain and service mechanical

equipment; prepare appropriate engineering report.; carry out plant installation and

maintenance; apply management principles in organizing supervisory groups and in the

arrangement of sequence of activities; acquire and display basic entrepreneur skills and apply

adequate Information Technology (IT) skills (NBTE , 2003). Engineering graphics is one of

the core courses for students of National Diploma in Mechanical Engineering Technology in

the Nigeria Polytechnics. It involves construction of different geometric figures and shapes,

orthographic projections, orientation of objects in space, developments of objects and

intersections of regular solids and planes (NBTE, 2003).

Graphics is a real and complete language used in the design process for visualization

(Bertoline and Wiebe, 2005). A powerful tool for engineers is to see in their minds the

solution to problems. Visualization is the ability to mentally picture things that do not exist.

Bertoline and Wiebe explained that design engineers with good visualization ability not only

are able to picture things in their minds, but also are able to control that mental image,

allowing them to move around the image, change the form, look inside and make other

movements as if they were holding the object in their hands

Engineers communicate with one another largely by graphics. According to Yusuff

(2005) graphics language are bound by rules and are used to communicate ideas and feelings,

convey information and specify shapes by use of visual symbols such as points, lines, planes

and textures or surface qualities. It is a language of the industry used by engineers to convey

ideas and actions to be taken on issues, plans and designs. Jensen and Helsel (1996) were of

27

the opinion that graphics representation means dealing with the expression of ideas by lines or

marks impression on a surface. Jensen and Helsel described graphics as a language of the

industry. They explained that even in the highly developed world, languages are inadequate

for describing the size, shape and relationship of physical objects hence, for every

manufactured object there are drawings that describe its physical shape completely and

accurately, communicating engineering concepts to manufacturing. Therefore, all mechanical

engineers are taught graphics so that they will be skilled at making and interpreting

mechanical drawings. Ulman, wood and Craig (1990) explained that drawing are

representations of a final design (the end product of the design process) and engineers are

intended to archive the completed design and communicate it to other designers and

manufacturing personnel.

AutoCAD – Ergonomics and Techniques of Graphics in AutoCAD Environment

AutoCAD is one of the Computer-Aided Design (CAD) software packages currently

available for graphics design. It is an interactive drafting software package for construction of

objects on a graphics display screen. According to Bui (2004) AutoCAD is a vector graphics

software developed in the early 1980s by Autodesk incorporation for Two-Dimensional and

Three-Dimensional design and drafting. It uses primitive entities such as lines, polylines,

circles, arcs and text as the foundation for more complex objects (Wikipedia, 2007).

Specifically, AutoCAD was first released in December 1982 for computers that used the Disk

Operating System (DOS) (Whelan, 1994). Supporting this view, Finkelstein (2002) pointed

out that even though AutoCAD came in 1982 running under DOS, it was the first significant

CAD program to run on a desktop computer as at the time other CAD software packages ran

on high-end workstation or even main frame.

Since the inception of AutoCAD, it has progressively kept pace with the advancement

in the computer/Information Technology (IT) Industry. Today AutoCAD is recognized as one

of the most powerful CAD software packages (Texas Academic and Management, 2000). Its

success has been attributed to its famous open architecture i.e many source code files in plain

text (ASCII) files that can easily be customized, and programming languages (such as

AutoLIPS and Visual Basic for Applications) designed especially so that the end user can

program AutoCAD. As a result, AutoCAD is the most flexible drafting program available

which has application to all fields of human endeavour (Bronitz and Bills, 2002). Some of the

major disciplines that use AutoCAD according to Finkelstein (2002) are Architectural (also

called AEC for architectural, engineering, and construction), Mechanical, GIS (Geographic

Information System), Facilities management, Electrical/Electronic, Multimedia. AutoCAD

28

also has many other lesser-known uses, such as pattern making in the garment industry, sign

making and so on. Yarwood (1996) added that AutoCAD is made flexible so that it has

applications in schools and colleges. Figure 1 below shows AutoCAD in its default display.

Figure 1: AutoCAD in its default display

The Menu and Toolbar s- At the top of the screen is the title bar, and directly beneath

the title bar is a menu bar. Below that are two rows of bars. In addition, the screens has two

more tool bars, - the draw and modify toolbars, which are probably docked at the left side of

the screen as shown in Figure 1 The menu and toolbars are used together to give AutoCAD

commands to draw, edit, get information and so on (Alice, 2001).

The drawing Area - This is the blank black area in the middle of the screen. It is the

graphics window where the users draw. The area can be changed to white depending on user’s

choice. It is just like a sheet of drafting paper. AutoCAD drawing area is said to be divided

into a number of equally spaced units in both the horizontal and vertical directions. The

horizontal units can be stated in terms of x and the vertical units in terms of y (Yarwood,

1996). He explained further that this system of dividing an area into units in terms of x, and y

is known as Cartesian coordinate system.

Cursor (Crosshairs) - These are the two intersecting lines with a small box at their

intersection. The small box is called the pickbox because it helps the user to pick objects

while the lines are called crosshairs (Finkelstein 2002). As the mouse is moved in the drawing

area the cusor shows the location of the mouse in relation to other objects in the drawing area

(Bronitz and Bills, 2002).

Status bar/ Status Line - At the bottom of the screen is the status bar as shown in

Figure 1. At the left are the x, y, and z, coordinates box. This is called the coords box whose

function is to update the intersection of the cursor cross hairs in x,y coordinate numbers

(Yarwood, 1996). According to Bronitz and Bills (2002) as the mouse is moved around the

29

drawing area, the x, y and z coordinate change. The status bar also contains several buttons

such as SNAP, GRID, ORTHO, POLAR, OSNAP, OTRACK, LWT and MODEL.

The Command line - At the bottom of the screen, just above the status bar is a

separate horizontal window called the command window. This is the window where

AutoCAD displays responses to user input. By default, it shows three line of text. (It can be

changed to show as many lines as one likes). AutoCAD commands are called user interface

(Yusuff, 2006). The use of this command provides human and computer interface. According

to Alice (2001) AutoCAD provides user with command prompt which user must read and

respond as needed. A command is a single-word instruction user give to AutoCAD telling it to

do something, such as draw line (Omura, 2003). Whenever user invokes a command,

AutoCAD responds by presenting messages to the user in the command window or display a

dialog box. The messages in the command window often tell the user what to do next, or

offer a list of option, usually shown within square bracket. The commands are important

because users of AutoCAD cannot do anything in AutoCAD without executing a command.

In a word processing program for example, it is possible to start typing, in a spread sheet

program, it is possible to start entering data but nothing happens in AutoCAD until the user

gives AutoCAD a command to execute (Finkelstein, 2002). All commands can be executed

by typing the command on the command line. Even where a menu item or toolbar is used to

execute a command, user needs to look at the command line to see how AutoCAD responds.

Often, AutoCAD provides options that must be typed in, from the key board and anything

typed appears on the command line. For instance, when user types in coordinates specifying

points, they appear on the command line.

The UCS Icon - In the lower-left corner of the drawing area is an L-shaped arrow

Figure 2. This is the User Coordinate System (UCS) icon. Omura (2003) noted that the UCS

icon tells AutoCAD user his orientation in the drawing. The arrows point to the positive

directions of the X and Y axes to help users keep their bearing (Finkelstein, 2002).

Figure 2: The UCS icon in its default display

In addition, the X and Y arrows indicate the x- and y- axes of drawing while

the little square at the base of the arrow indicates that the user is in what is called the World

30

Coordinate System (WCS) (Omura, 2003). Whelan (1994) noted that the AutoCAD’s world

coordinate system consists of three axes at an angle of 900 to each other as shown in Figure 3.

Similarly, Bertoline and Wiebe (2005) pointed out that AutoCAD world coordinate system

uses a set of three numbers (x,y,z) located on three mutually perpendicular axes and measured

from the origin (0,0,0). This is the point at which (x,y,z)=(0,0,0). Whelan explained further

that AutoCAD presents the world coordinate system as if the user is looking directly down the

Z-axis as shown in Figure 3. In the world coordinate system the Z axis is said to have a

constant value of 0 (Texas Academic and Management Consult, 2000).

Figure 3: World Coordinate System with three axes (X, Y and Z) at an angle of 900 to each other

According to Bronitz and Bills (2002) the world coordinate system is a global system

of reference from which user can define other User Coordinate Systems (UCS) when working

with the three-dimensional coordinate. Omura (2003) explained that it may help to think of

these AutoCAD user coordinate systems as different drawing surfaces. In AutoCAD users can

draw as he would in the WCS with 2-D coordinate, yet draw a 3D image. Also, AutoCAD

user can have several User Coordinate Systems at any given time. For instance, users can

change viewpoint to the UCS to have UCS South East Isometric as shown below:

Figure 4: the UCS at 3-D Isometric

Furthermore, one aspect of AutoCAD, and many other CAD programs, is that the

geometric construction relies heavily on the understanding of the Cartesian Systems (x,y and

31

x,y,z) and the ability to relate it to the object in space. Often when working with AutoCAD,

particularly in three-dimesion, user must change the orientation of the X, Y, and Z planes to

suit the needs of the drawing process. In AutoCAD, variations of the Cartesian System are

referred to as the User Coordinate System (UCS) (Alice, 2001). He explained further that the

User Coordinate System allows Users to reposition the location of the origin point (0,0,0) and

the X, Y, and Z axes during a model's construction. In this regard, Bertoline and Wiebe (2005)

refer to a user coordinate system as a moving system that can be positioned any where in 3-D

space by the user to assist in the construction of geometry. However, the UCS icon can be

turned off completely. According Finkelstein (2002) if user is not working with customized

UCSs, user often has no reason to see the UCS in when working with Two-Dimensional

coordinate technique.

Techniques of Graphics in AutoCAD Environment

Before the advent of Release 10 version of AutoCAD, it was a fully self-contained

two-dimensional CAD software. The advent of release 10 capable of 3-D coordinate system

marked a remarkable turning point in AutoCAD techniques and applications (Texas Academic

and Management Consult, 2000). Hence, techniques of graphics in AutoCAD nowadays

involves the use of Two-dimensional (2-D), and Three-Dimensional (3-D) Cartesian

coordinate system. For every two-dimensional coordinate system there is a three-dimensional

counterpart of it (Bertoline and Wiebe, 2005; Finkelstein, 2002). For instance, for every

absolute coordinate (0,0) in 2-D, there is a corresponding absolute coordinate (0,0,0) in 3-D.

Different types of 2-D and 3-D Cartesian coordinate system are discussed below:

AutoCAD Two-Dimensional (2D) technique

A two-dimensional system establishes an origin at the intersection of two mutually

perpendicular axes labeled X (horizontal) and Y (vertical) (Bertoline and Wiebe, 2005).

Similarly, Jensen and Helsel (1996) explained that a two-dimensional coordinate system

consist of a fixed point (point of origin) and two orthogonal (the angle between them is 90

degrees) straight lines (coordinate axes) intersecting at this point. Each coordinate axis is

given a direction in which its values grow on a scale. One coordinate axis (X-axis) is called

abscissa axis, another (Y-axis) is called ordinate axis. In essence, two-dimensional (2-D)

system consists of a pair of lines on a flat surface or plane, which intersect at right angles. The

lines are called axes and the point at which they intersect is called the origin. The axes are

usually drawn horizontally and vertically and are referred to as the x- and y- axes, respectively

as shown in Figure 5

32

Figure 5: Two-Dimensional coordinate system

As shown in the figure 5, the origin is assigned the coordinate values of 0,0. Values to

the right of the origin are considered positive, and those values to the left are negative.

Similarly, values above the origin are positive, and those values below are negative. Using

this convention, users of AutoCAD can locate any point in space by assigning a unique set of

numbers to that point. The numbers assigned to each point are called coordinates, where the

first number is the X coordinate and the second number is the Y coordinate. The universal

accepted convention in specifying a point with two-dimensional technique in AutoCAD is to

put the X coordinate first, then a comma, and then the Y coordinate (Omura, 2003;

Finkelstein, 2002; Bronitz and Bills,2002). Hence, In AutoCAD, a two-dimensional technique

involves using two coordinates (x,y). Several forms of 2-D coordinates system include;

absolute coordinate, relative coordinate and polar coordinates.

Absolute Cartesian coordinate- coordinate input for absolute coordinate is based on

the horizontal and vertical measurement system. All absolute distances are described in terms

of their distance from the origin 0,0. Usually, absolute coordinate are used in AutoCAD when

the values of X and Y coordinates are known. For instance, an absolute coordinate is used

when a line is drawn by entering the actual coordinate such as a line from 3,2 to 6,9. For

instance, the rectangle below is defined by (0,0,), 4,0), (4,2) and (0,2)

Figure 6: Rectangle constructed with absolute coordinate of 2-D coordinate system

Relative Cartesian coordinate- Relative coordinates specify the X and Y distance

from a previous point. According to Yarwood (1996) relative coordinate involves entering

33

coordinate numbers which are relative to the previously entered coordinate. They are called

relative coordinate because they only have meaning relative to a point previously specified

(Finkelstein, 2002). Bertoline and Wiebe (2005) noted that relative coordinate are always

referenced to a previously defined location and are sometimes referred to as delta coordinates,

meaning changed coordinates. Similarly, Jensen and Helsel (1996) explained that a relative

coordinate is located with respect to the current access location (last cursor position selected)

rather than the origin (0,0). Relative coordinate are specified by using @(x,y). For example a

vertical line of 2mm can be drawn from any point in a 2-D space reference to that previous

line by specifying @0,2. AutoCAD creates a line starting from the first point, ending two

units along the y- axis. Relative Cartesian coordinates are often used for lines which are

drawn either horizontal or vertical. These are called orthogonal lines. For example the

rectangle below is defined by (0,0), (@4,0), (@0,2), (@-4,0)

Figure 7: Rectangle constructed with relative coordinate of 2-D coordinate system

Polar coordinate- Polar coordinate is similar to a relative coordinate because it is

positioned with respect to the current access location. According to Jensen and Helsel (1996)

with a polar coordinate system a line is specified according to it actual length and a direction

rather than as X and Y coordinate distance. Supporting this view, Yarwood (1996) explained

that the length and angle of the next point is entered in the form of @distance<angle e.g

@50<60, where the length of the line is 50mm long and is inclined at angle of 60 degrees to

the previous position. Yarwood explained further that when lines at angles are drawn in this

manner, the default system of angular measurement is in degrees in an anticlockwise direction

with east being 0 degree.

In addition to the different types of two-dimensional coordinate techniques which can

be used in AutoCAD. AutoCAD also provides user with a system of drawing in Isometric

mode. Isometric mode provides a two-dimensional space for drawing isometric objects. When

using this mode, the crosshair represents the X- and Y-axes as shown in Figure 8. Once in

34

Isometric mode, user can press function key 5 (F5) to toggle from plane to plane when

constructing a isometric objects.

Figure 8: AutoCAD Isometric mode showing an Isometric cube and the crosshair representing X- and Y- axes

For example while in the Isometric mode, absolute, and polar coordinate of 2-D coordinate can be

used to construct an isometric object as shown below;

Figure 9: Isometric object constructed with absolute and polar coordinate of 2-D coordinate system

AutoCAD Three-Dimensional (3-D) Technique

In a Three-Dimensional coordinate system, the origin is established at the point where

three mutually perpendicular axes (X, Y, and Z) meet (Bertoline and Wiebe, 2005). Jensen

and Helsel (1996) explained that the Three-Dimensional coordinate system consists of fixed

point (point of origin) and three straight lines (coordinates axes) intersecting at the fixed

point: the lines belong to different planes and are pair-wise orthogonal (the angle between

each pair is 90 degrees). Each coordinate axis is given a direction in which its values grow on

a scale. One coordinate axis (X-axis) is called abscissa axis, the second (Y-axis is called

ordinate axis and the third (Z-axis) is called applicate axis. Figure 9 shows a three

dimensional coordinate system.

35

Figure 10: Three-Dimensional coordinate system

In the three-dimensional coordinate system above the origin is assigned coordinate

values of 0,0,0. By convention, values to the right of the origin are positive, and those to the

left are negative values; values above the origin are positive and those to the below are

negative; and values in front of the origin are positive and those behind are negative. Using

this convention, users of AutoCAD can assign a unique triplet of ordered numbers to any

point in space. The first number represents the X distance, the second number represents the Y

distance, and the third number represents the Z distance.

Generally, the universal accepted convention in specifying a point with three-

dimensional technique in AutoCAD is to put the X coordinate first, then a comma, followed

by the Y coordinate, a comma and then the Z coordinate (Omura, 2003; Finkelstein, 2002;

Bronitz and Bills,2002). Therefore, In AutoCAD, a three-dimensional technique involves

using three coordinates (x,y,z). Several forms of 3-D coordinates system include; absolute

coordinate, relative coordinate, cylindrical coordinates and spherical coordinate

Absolute coordinate– absolute coordinates are always referenced to the origin (0,0,0).

For example the rectangle in the figure below was drawn by Bertoline and Wiebe (2005). The

rectangle is defined by corners that have absolute coordinate values of (0,0,0), (4,0,0), (4,2,0),

(0,2,0).

Figure 11: Rectangle constructed with absolute coordinate of 3-D coordinate technique

36

Relative coordinate - just like in a relative coordinate of two-dimensional coordinate

system, a relative coordinate of 3-D are always referenced to a previously defined location.

Figure 12 shows the same rectangle in Figure 11 constructed using the relative coordinate

system of three-dimensional coordinate system where point B has values of 4,0,0 relative to

the origin 0,0,0 at Point A; C is referenced from B and has relative values 0,2,0; D is

referenced from C and has relative values -4,0,0.

Figure 12: Rectangle drawn with relative coordinate of 3-D coordinate technique

Cylindrical coordinates- cylindrical coordinate involves one angle and two distances. It

specifies a distance from the origin, an angle from X axis in the X-Y plane, and a distance in

the Z direction (Bertoline and Wiebe, 2005). A cylindrical coordinates have the format

@distance < angle, distance. Where:

• The first distance is the number of units in the XY plane from the origin (for absolute

coordinate) or the last point (for relative coordinate)

• The angle is the number of degrees from the X axis in the XY plane

• The second distance is the number of units along the X axis

Example of a line drawn using cylindrical coordinate system is shown below:

Figure 13: Line drawn with cylindrical coordinate

Spherical coordinates- the spherical coordinate are used to locate points on a spherical

surface by specifying two angles and one distance. It specifies a distance from the origin on a

37

line that is at an angle from the X axis in the X-Y plane and then an angle away from the X-Y

plane. Spherical coordinates have the format @ distance < angle < angle. Where:

• The first distance is the total number of units from the origin (for absolute coordinates)

or the last point (for relative coordinates)

• The first angle is the number of degrees from the X axis in the XY plane

• The second angle is the number of degrees from the XY plane in the Z direction.

Example of a line drawn with spherical coordinate is shown below:

Figure 14: line drawn with Spherical coordinate system

In AutoCAD, the 3-D coordinate system can also be use when in AutoCAD 3-D isomteric to

construct an Isometric object has shown below;

Figure 15: Isometric object constructed with 3-D coordinate system in a 3-D South East isometric

Spatial Ability and its Importance to Students’ Achievement in Engineering

Graphics

Spatial ability is an important component of human intelligences (Kaufmann,

Steinbügl, Dünser and Glück, 2003). According to Smith (2002) spatial ability is an

important, distinct aspect of human intelligences identified by Howard Gardner (founder of

multiple intelligence theory) which in Gardner’s word is used to formulate mental images and

to manipulate the images in the mind. The Columbia Encyclopaedia, Sixth Edition (2005)

38

defined intelligence as the general mental ability involved in calculating, perceiving, forming

relationships and analogies, classifying, learning quickly, storing and retrieving information,

using language fluently, generalizing, reasoning, and adjusting to new situations. Basham

(2007) reported that intelligence can be divided into two, namely: Crystallized intelligence

and Fluid intelligence. Crystallized intelligence represents the sum of acquired knowledge and

experience, or what a person knows and is usually measured with tests of verbal knowledge

and general information. While fluid intelligence represents the ability to reason and apply

information in new situations, and is usually assessed with tests of general reasoning ability

and also with math and spatial ability measures. In this context, Basham noted that spatial

knowledge involves crystallized intelligence, while spatial ability predominantly involves

fluid intelligence.

Spatial ability is also defined as a cognitive function that makes it possible for human

being to deal effectively with spatial relations, visual-spatial tasks and orientation of objects in

space (Sjolinder, 1998). Basham (2007) added that spatial ability is more than mental pictorial

representation; it includes analysis of structural relationships so that operational thought can

take place. Petersen (1985) define spatial ability as the mental process used to perceive, store,

recall, create, edit, and communicate spatial images. According to Lohman (1993) spatial

ability is the ability to generate, retains, retrieved and transforms well-structured visual

images. He explained that there are several spatial abilities, each emphasizing different

aspects of the process of image generation, storage, retrieval and transformation. Similarly,

Pittalis, Mousoulides and christou (2002) opined that spatial ability implies the generation,

retention, retrieval and transformation of Visio-spatial information and is used in problem

solving activities which particularly require the processing of Visio-spatial information. Allen

(1999) defined spatial ability in terms of components of spatial skills as follows: mentally

seeing two-dimensional elements in a three-dimensional surrounding; visualizing the three-

dimensional environment from a two-dimensional drawing; mentally rotating objects to

another plane; and visualizing objects in space. From the above definitions, spatial ability

can be defined as the ability to think in picture, to create mental images and to transform

visual or spatial ideas into imaginative and expressive creation.

There are different categories of spatial ability. These are mental rotation, spatial

visualization, perception, orientation and imagery. Mental rotation is the ability to mentally

rotate a single stimuli object in the mind in order to envision it from different angles (Zacks,

Mires, Tversky, and Hazeltine, 2000). Mental rotation involves the ability to rapidly and

accurately rotate a 2-D or 3-D-figure (Maier, 2005). He maintained that nowadays this ability

39

becomes more and more important, because many people work with different graphics

software.

Strong and Smith (2002) defined spatial visualization as the ability to mentally rotate

in space two-and three-dimensional objects with one or more movable parts. Alonso (1998)

described spatial visualization as ability to image the rotation of depicted objects; the folding

or unfolding of flat patterns; the relative changes of object’s position in space; and the motion

of machinery. He stated that spatial visualization is a factor which is best assessed in test that

present a stimulus pictorially and in which some manipulation of transformation to another

visual arrangement is involved. Supporting the above definition, Basham (2007) described

spatial visualization as an ability to visualize a configuration in which there is movement or

displacement among the internal parts of the configuration. Koch (2005) emphasized the

dynamic dimension of spatial visualization when he noted that it is an ability to comprehend

imaginary movements in three-dimensional space or the ability to manipulate objects in the

imagination. It is interesting to note that Koch specified the three-dimensionality of the space

involved. Velez, Silver and Tremaine (2005) in their own submission asserted that spatial

visualization is an ability to manipulate or transform the image of spatial pattern into other

arrangements. The underlying ability in spatial visualization appears to be connected to

movement, transformation and manipulation. It is dynamic and involves motion. Thus, spatial

visualization is the ability to mentally manipulate, rotate, twist, or invert a pictorially

presented stimulus object.

The term imagery is associated with visualization. Visual imagery means imagery

which occurs as a picture in the mind’s eye (Velez et al., 2005). Two types of imagery are

kinetic and transformational. Basham (2007) explained that kinetic imagery is based on one’s

experience of an object’s movement which allows an individual to judge whether an

approaching object is likely to hit its target while transformational imagery allows the mental

view of an object as it changes shape or form. This requires mental manipulation of a visual

image from a different perspective such as imagining the shape change of an object which has

moved (Potter and Van der Merwe, 2001).

The spatial perception category of spatial ability is a sensation in the brain occurring in

the immediate presence of stimuli (Lahav, 2006). The way an individual relates to space is

fundamental to spatial perception. Spatial perception is central to the process of cognition

across all disciplines. Recent research in the field of geography for example, suggests that

development in spatial perception, conceptualization and knowledge of the environment is

essential to the process of learning and teaching in that field. Perception in general is the

gathering of information through our senses and the organizing of that information in order to

40

create meaning. It is subjective and relative and depends on the way in which individuals

structure it at different times. As individuals make sense of their experiences, perceptions

change constantly. Velez et al. (2005) thus suggests that spatial perception is particularly

relates to how an individual perceives space. The extent of an individual’s spatial perception

according to Maier (2005) depends on spatial perceptual skills that comprise among others the

ability to: recognize object in the environment; orientate ourselves in the world; orientate

objects in relation to other, ourselves and/or objects; transfer three-dimensional space to two-

dimensional forms; achieve perceptual constancy (recognition that real objects are constant in

shape, size and colour, but that they may appear distorted when viewed from different

perspectives); recognize depth and distance/proximity; identify perceptions of elevations

including vertical/aerial, oblique and horizontal/normal views; identify and understand

relationships of location/position, scale and size.

Tremblay (2004) described spatial orientation as the ability to recognize the identity of

an object when it is seen from different angles. This also involves the ability to visualize a

rigid configuration when the object is moved into different positions and the comprehension

of the arrangement of elements within a visual stimulus pattern, the aptitude to remain

unconfused by the changing orientations in which a spatial configuration may be presented

(McCarty, 2007). Branoff (1998) described spatial orientation as the ability to perceive spatial

patterns accurately and to compare them with each other. An important feature of spatial

orientation is the ability to make sense of spatial orientations of objects relative to different

positions of itself or of other objects. McGee (1979) reported that spatial orientation involves

the comprehension of the arrangement of elements within a visual stimulus pattern, the

aptitude to remain unconfused by the changing orientations in which a spatial configuration

may be presented, and the ability to determine spatial orientation with respect to ones body.

Spatial ability is fundamental to human functioning in the physical world. In order to

interpret, understand, and appreciate our inherently geometric world, spatial understanding is

necessary (Lowrie, 1994). According to Newcombe and Huttenlocher (2000), as the use of

tools and making of artifacts became part of the human repertoire, the ability to imagine and

construct useful implements and materials likely increased reproductive advantage. Alonso

(1998) also noted that in order to mentally explore and travel within our environment, we

need to be able to represent visual and spatial images in our minds. According to him, this

means that human beings need to be able to store two-and three-dimensional information in a

way such that he/she can retrieve these representations and manipulate them as needed. In

addition, the ability to represent and process spatial information is important for many

41

common activities, such as finding our way to and from places in the environment, moving

furniture, packing a suitcase, and catching a ball (Hegarty and Waller, 2005)

Spatial reasoning enables an individual to use concept of shapes, features and

relationship in both concrete and abstract ways, to make and use things in the world, to

navigate, visualize and to communicate (Newcomer, Raudebaugh, McKell and Kelly, 1999).

In a similar way the ability is used to envision new things and establish relationship of

concepts in the mind (Jones and Bills, 1998). According to Basham (2007) spatial ability is

basic to higher level activities such as mathematical thinking and use of information presented

in such representation as maps, graphs, diagrams and other spatial layout. Basham explained

further that it is even basic to the understanding of verbal descriptions of spatial material such

as following directions and instructions for hooking up electronic equipment.

According to McGee (1979) strong spatial skills have been shown to correlate to

success, achievement, and retention in engineering programs. Supporting this assertion, Olkun

(2003) noted that spatial thinking is used to represent and manipulate information in learning

and problem solving in engineering design. Spatial ability has also been identified as one of

the most important skills related to achievement in engineering and technical graphics because

of its direct relationship to the graphical communication associated with design (Koch, 2005).

It is particularly important to achievement in engineering because engineers must be able to

solve problems involving abstract objects and be able to communicate those solutions and

understand the drawings or solutions of others (Alias, Black and Gray, 2002). In order for

engineers to be able to prepare and interpret engineering drawing of mechanical equipment in

mechanical design, the engineer must be able to visualize how all the components in the

system work (Medina, Gerson and Sorby, 2000). According to Robichaux (2003) the ability

to create a mental image of an object and then to manipulate it mentally has significant

practical application in fields of engineering and design. In this context, Strong and Smith,

(2002) noted that spatial visualization is an established element of engineering graphics and is

integral for success in graphics and engineering as a whole. According to Sueoka, Shimizu

and Yokosawa (2001) development of spatial ability required for visualization is one of the

main purposes of engineering graphics education. They explained that freshman in graphics

require spatial ability for two reasons. First, a three-dimensional object can be recognized via

a two-dimensional graphics only when the viewer has advanced visual spatial design

information processing abilities. Secondly, a more suitable spatial design can be realized in

actual designing work by improving the level of spatial visualization skills. Besides, the

development of a general spatial ability is an important factor associated with geometric

understanding (Bishop, 1980), which is an aspect of engineering graphics. Having a mental

42

image of a parallelogram or circle is fundamental in geometry. Without spatial sense, students

may act mechanically with shapes and symbols, having little understanding of their meaning

and relevance (Reynolds and Wheatley, 1999).

In addition, spatial ability is important for reasoning in technical domains (Medina,et,

al. 2000). Zacks, Mires, Tversky and Herzeltine (2000) stated that the ability to imagine and

reason about changes of objects and their spatial layout is important, both for everyday

cognition and for reasoning in technical domains. In this context, Kinsey (2003) noted that

good spatial conceptualization is a necessity for engineering as well as other mathematics and

science disciplines. Similarly, Scribner and Anderson (2005) pointed out that well developed

spatial skills have been proven to be critical to a technical person’s ability to develop creative

design solution to engineering problems. Even, in cases where non-spatial strategies are

required, spatial ability influences the degree to which a problem solver is able to develop and

evaluate strategies (Alias et al., 2002). This is because problem solving commonly uses

perceptual representations to partially encode the problem elements involved, which is helpful

in supporting inferences (Basham, 2007). Besides, in problem solving, a mental model must

first be created and regardless of the representation, the mental construction is most important

for problem solving (Jonassen, 2000).

Proficiency in spatial skills has also been linked to creativity. According to Allen

(1999) visualizing a three-dimensional image and mentally rotating and transforming it

provide a designer with multiple creative ideas for a design solution. He explained that this

mental transformation helps achieve a delicate balance between reality and fantasy. The more

ideas a designer can brainstorm, the better the ability to realize the most creative solution. The

ability to concisely communicate a highly complex and creative design solution has at its

creative core visualization skills (internal imaging) that allow designer to mentally create,

manipulate and communicate solutions effectively.

Spatial ability is considered to be closely related to academic achievement, particularly

to success in mathematics. In addition to general intelligence, mathematical reasoning is

typically thought to require abilities associated with visual imagery, as well as the ability to

perceive, number, and space configurations (Hegarty and Waller, 2005). There is a

substantial literature in which relations between factors of spatial ability, such as

visualization, mental imagery, and mathematical performance have been investigated (e.g.

Bishop, 1980; Presmeg, 1992). The importance of spatial ability to the development of

mathematical thinking is supported by many researchers (Bishop, 1980; Tartre, 1990;

Gutiérrez, 1996). They maintained that the skills of spatial orientation and spatial

visualization contribute meaningfully to predicting mathematics achievement. According to

43

Keller and Hart (2002) numerous correlation studies have shown that spatial ability is

positively related to mathematics achievement. Developing spatial sense, as well as number

sense, is a fundamental goal of mathematics instruction that develops skills in problem

solving in particular and doing mathematics in general. Strong spatial sense permits students

to formulate image-based solutions to mathematics problems.

One of the important characteristics of spatial ability is that it can be improved in both

children and adult. Bertoline (2003) pointed out that spatial skills are developed through life

experiences. He explained that children who are exposed to appropriate learning environments

would have stronger spatial visualization skills later in life. Spatial ability of students studying

mechanical engineering technology can be improved. According to Olkun (2003) the skills

needed to develop engineering students’s spatial ability are acquired through programs or

activities that teach engineering or drafting (Olkun, 2003). In drafting, students are introduced

to orthographic and multi-view projections using various multifaceted shapes. Educators seek

to develop or enhance students’ visualization skills through a series of drawing exercises. The

first basic concepts of projection are explained and practiced using simple, solid objects such

as rectangles, triangles, cylinders, and cones (Croft, Meyers, Boyer, Miller, and Demel, 1989).

Supporting this view, Mackenzie and Jansen (2005) explained that the primary goal in

technical drawing or drafting courses is to help students develop the knowledge and skills

needed to function as craftsmen and technologists. Such courses, particularly in the early

years of a student’s academic life, are designed to facilitate the development of skills related

to technical graphics concepts, creativity and spatial related problem-solving abilities.

However, the traditional instructional design of demonstration with large manual

drawing instruments offers limited utility when used to teach graphics/drafting. One of the

major limitations of the method is the problem of presenting three-dimensional (3-D) spatial

information in a two-dimensional format (2-D) (Mackenzie and Jansen, 2005). Accordingly,

many students taught graphics with the method have difficulty in comprehending the graphics

representation of three-dimensional objects (Scribner and Anderson, 2005). In view of the

problem inherent in the use of demonstration with large manual drawing instruments on the

chalk board, numerous studies have been conducted in many countries of the world to identify

instructional techniques that will enhance the development of students’ spatial ability in

graphics. Several of these studies have compared the effectiveness of instruction using CAD

software packages with the traditional demonstration of board drafting. Such studies include

Basham (2007), Godfrey (1999), Braukmann and Pedras (1993), and Johnson (1991). Results

from many of these studies showed that instructional design with CAD packages is effective

in developing students spatial ability in graphics. Hence, in order to help National Diploma

44

students studying mechanical engineering technology attain a minimum proficiency in their

spatial skills so that they can then actively perform their function as mechanical engineering

technologist an appropriate technique of CADD must be adopted.

Improving Students’ Spatial Ability in Engineering Graphics with the Use of Computer-

Aided Design Packages

Engineering graphics have been used to communicate ideas from ancient times to the

modern era. As the vernacular of industry, engineering graphics is essential to the curricular

of all technology, engineering and design programs. The primary goal in engineering graphics

courses is to help students develop the knowledge and skills needed to function as

technologists, engineers, drafters and designers. The course is designed to facilitate the

development of skills related to technical graphics, design/drafting concepts, creativity and

spatial abilities.

The importance of visualization and spatial skills has received growing recognition.

Strong and Smith (2002) reported that, in 1983, Eliot and Smith identified three distinct

phases of the history on spatial visualization research. Phase One (1901-1938) dealt with an

attempt by psychologists to identify a single spatial factor. Prior to this phase visual tasks

were not considered an indicator of intelligence. Verbal tasks were viewed as the major

indicator of intelligence. Several studies during this time led to the identification of a spatial

factor that was important in determining intelligence. These studies established visualization

as an important aspect of intelligence. Phase Two (1938-1961) began to identify several

spatial factors and theorize how these factors varied. Two major categories of spatial factors

were identified. The first dealt with the ability to recognize spatial configurations. The second

included the ability to mentally manipulate those configurations. Measurement tools for the

various spatial factors using pencil and paper tests were developed. It was during this time

that the term spatial visualization arose. Phase Three (1961-1982) was an attempt to further

separate the various spatial factors and establish sources of variation in them. Many studies

found that age, sex, and experience were all sources of variation effecting individual

differences in spatial ability. Since Eliot and Smith discussed these three phases in 1983,

fourth phase has emerged in engineering graphics. Phase four deals with the process of

establishing the effects of computer technology on spatial visualization skills and the

subsequent measurement of these skills. This research began with establishing the computer

as an effective 2-D design tool and continues today using 3-D design tools (Strong and Smith,

2002). It was in this context, Basham (2007) pointed out that recent attention to spatial ability

45

in engineering graphics is largely due to the vast changes in computer technology and

Computer-Aided Design (CAD) software packages.

Spatial ability is multifaceted, providing diverse spatial activities is the key to

enhancing overall spatial visualization ability (Alias et al., 2002). CAD packages in addition

to teaching students about shapes and spatial relations, provide diverse activities which can

help improve spatial ability. These activities include the use of two- and three-dimension

Cartesian coordinate techniques to locate points in 2-D and 3-D space, use of animation,

interaction with virtual objects and automation of conversion of two-dimensional object to

three-dimensional object and vice versa. According to Robichaux (2003) the more a subject

participated in spatial activities such as drawing in two- and three-dimension, the higher

his/her spatial test scores. When using CAD software according to Basham (2007) in a 3-D

space, one no longer deals with only x and y coordinate, but also with the z-axis as well. Most

3-D software applications provide different perspective views to provide the user a better

sense of an object’s orientation in space (Mohler, 2006)

The word Spatial means of relating to, involving, or having the nature of space (Isaac

and Marks, 1994). Spatial ability is the intellectual ability primarily used to function and

operate in 2- or 3- dimensional spaces (Bannatyne, 2003). The 2-D and 3-D Cartesian

coordinate system locates the positions of geometric forms in 2-D and 3-D space. The

coordinate geometry based on this system theorizes that for every point in space, a set of real

numbers can be assigned, and for each set of real numbers, there is a point in space (Bertoline

and Wiebe, 2005). According to Branoff (1998) addition of coordinate axes enhances mental

rotation tasks which improve spatial ability.

Animation is a tool for improving spatial visualization performance in students.

Animation is capable of providing both real and apparent motion which adds realism that

results in improved viewer perceptions of the relations between objects (Blake, 1997).

Computer animation takes advantage of its ability to provide meaning, to illustrate, and to

give organization to the material being taught (Profit and Kaiser, 1996); therefore, animation

is used in many fields of study (Bodner and Guay, 1997; Strong and Smith, 2002). Research

on animation includes work that has compared animation to still images, text only, still

images with text, and motion pictures (video). Prior to the current standards of computer

animation, motion pictures were consider by some researchers as “far superior” compared to

still images with or with text (Shubbar, 1990). Mayton (1991) noted that animated visuals

allowed better retention in students’ learning and communicated ideas involving time and

space better than text. Viewer controlled animation provides significantly improved depth

perception and increases conceptual ideas through the development of mental models

46

(Williamson and Abraham, 1995; Wiley, 1990). Additionally, viewer controlled animation

leads to improvement in cognitive, perceptual, and motor skills and allows the creation of a

three-dimensional simulated world in which spatial performance can be developed, and also

assisting in anchoring the student into reality for the use of visual objects (Hart, 2003).

Training in spatial ability has adopted new and novel technologies, in particular use of

virtual reality to create an interactive 3-D computer-generated environment. Training became

more efficient and effective through visualization, animations and greater interaction with

virtual training objects (Rafi, Samsudin and Said, 2008; Mantovani, 2001; Moyer,

Bolyard,and Spikell, 2001). For instance, Cohen et al. (2003) found results in an experiment

that indicated it is possible to train participants to use mental rotation and perspective by

modeling these spatial strategies using animation. Interactive animation was found to be more

effective than non-interactive, especially for students whose initial tests indicated low spatial

ability. It was also found that students with low spatial ability spent significantly more time

viewing high quality videos and 3-D animations than did students who tested as having high

spatial ability. Three-dimensional CAD modeling software also allows such interaction, with

an emphasis on design. Therefore, it is beneficial to use a 3-D solid modeling package to

teach the fundamentals of computer drafting than 2-D non parametric software (Newcomer et

al., 1999). Three-dimensional CAD modeling is a way of representing certain aspect of

sensory world that can be difficult to comprehend in other way (Basham, 2007). Basham,

explained further that much ambiguity can be overcome when students view and produce 3-D

animation using CAD software package. Such software helps to deliver all the information

about objects in space simultaneously and also has the potential to activate alternative

knowledge structures specific to 3-dimesions; those that deal with visual-spatial orientation

and kinesthetic (Steed, 2001).

Mohler (2006) stated that although the particulars of identifying, measuring, and

improving spatial ability are often discussed, without developed spatial abilities, students are

hindered in the learning environment and within their chosen field. Multimedia has been

relatively successful as a learning tool because it draws upon more than one of the five human

senses, utilizing sight and sound, the two fundamental senses vital for information reception.

However, sight and sound are not enough to guarantee that students will learn from

educational material. In that case, the critical component of learning using digital learning

materials must be identified. Planned interactions are known to have a positive effect on

learning. These are probably the most critical components of any learning environment,

particularly computer-based ones. Interaction may come from teachers, peers, or the learning

materials themselves, but learning results from interaction and the level to which that

47

interaction is unique. According to Mohler, learning theorists assert that to cognitively

incorporate learning into long-term memory to reach an objective or to acquire a skill, the

learner must be actively involved through practice. “The interaction helps the learner reach

the objective and recall the information, skill, or behavior that was learned” (Mohler, 2006).

The relative effectiveness of different variations of hands-on interactivity used to learn spatial

visualization is an important issue for the pedagogy of computer-based learning (Smith,

2001).

Relationship between Gender and Spatial Ability

Gender literarily means the fact of being male or female. According to Nwameiye and

Osunde (2005) gender is a psychological term, which describes behaviours and attributes

expected of individual on the basis of being a male or a female. It refers to all the culturally

determined characteristics and the expected behaviour and roles of men and women which a

particular society has determined and assigned to each sex. One of the important discoveries

emerging from studies involving psychometric testing of spatial ability was the revelation of

gender differences favoring boys. In general, boys were consistently found to perform better

than girls on these tests suggesting that boys generally possess greater spatial skills than girls.

Male advantages in spatial ability have been established in studies by Nemeth and Hoffmann

(2006), Burin, Delgado and Prieto (2000), Medina, Gerson and Sorby (2000) and Branoff

(1998), Voyer, Voyer, and Bryden (1995), Linn and Petersen (1985), and Maccoby and

Jacklin (1974), where the trends of gender differences were found to be stable and consistent.

Thus, in studies where differences in spatial ability were evident males typically had stronger

spatial skills than girls.

However, it has been found out that differences in spatial ability of boys and girls does

not manifest until after puberty. McGee (1979) stated that the widely documented sex

difference on tests of spatial visualization and spatial orientation, as well as on numerous tasks

requiring spatial abilities, does not reliably appear until puberty. Supporting this view, Koch

(2006) explained that studies of younger children showed little or no spatial visualization

differences between males and females prior to puberty. After puberty, significantly different

levels were evident, with males having a higher ability. McGee (1979) noted that due to

spatial ability differences between boys and girls, a girl between the ages of 12 and 14, or

when puberty is occurring, who wishes to enter a field requiring high-level spatial skills

would need to obtain a very high score in relation to other girls in order to be competitive with

boys.

48

Another widely publicized reasons for the apparent sex differences in spatial ability

lies in the impact of the gap in spatial activities experienced by the two sexes. Berry (1966)

studied Temne and Eskimo percetrual skills and found that Temne and Eskimo female had no

differences in spatial ability from their male counterparts. Berry explained that the reason for

this finding is that Eskimo females shared equally in hunting and navigating, showing the

importance of experience in spatial ability. Basham (2007) in his own point of view noted that

the importance of the individuals’ interaction with the physical environment, such as play

with toys or sports activities that have a spatial components account for differences in the

spatial abilities of the two sexes. In the same vein, spatial experiences acquired through life

experiences or formal education has been suggested to contribute to differences in spatial

ability (Alias, Black and Gray, 2002). Deno (1995) in his study of the relationship of previous

experiences to spatial visualization ability found out that spatial experiences in non-academic

subjects are correlated to spatial ability in engineering students. He also found indications of

differential effects of spatial experiences on gender. For example, playing with construction

block type of toys is found to be a good predictor of male ability while activities that are

visual and less tactile are good predictors for females.

Hubana and Shirah (2004) also stated that gender differences in visio-spatial ability

are limited to active processing tasks such as mentally following pathways, but do not apply

to passive tasks such as recall of previously memorized positions. The ability to remember

object location is thought to require multiple separate processes. One has to encode the precise

positions occupied, assign the various objects to the relative correct locations, and achieve an

integration of both types of spatial information. It seems that the male advantage in spatial

memory is not a general effect but applies only to certain specific processing components

(Postma, Izendoorn, and De Haan, 1998).

However, there are empirical evidences pointing to the fact that spatial ability can be

improved in both male and female. For instance, studies by Kaufmann, Steinbugl, Dunser and

Gluck (2003) Baldwin and Hall-Wallance (2001) Branoff (1998) have indicated that females

could benefit as well as males from spatial training programs. Those studies have identified a

relationship between spatial activities participation and improvement of spatial ability.

Findings such as these have prompted the development of training programs in Visio-spatial

processing. According to Koch (2006) the use of solid modeling curriculum is an effective

way to close the gender gap in spatial visualization skills of boys and girls. Koch explained

further that visual cues regarding the rotation of an object have been shown to offset some of

the differences of males and females. He cited a study conducted by Branoff in 1998 where

Branoff examined the addition of coordinate axes on mental rotation tasks and found that

49

males scored higher on the preliminary test that did not have coordinates on the samples. The

three-dimensional coordinate system provides the three physical dimensions of space-height,

width, and length. When coordinates axes were added to the object, the females showed no

significant difference from the males. Branoff concluded that males tend to take a more

holistic approach to visualization and females more of an analytical approach. By adding a

reference, with the coordinated axes on the drawings, biases were eliminated.

Findings from experimental studies thereof have established evidence that spatial

ability is trainable when trainings are designed with specifics focus on this ability. It is evident

that greater participation in spatial activities resulted in higher performance in spatial task, and

both genders improved after spatial training. However, Baenninger and Newcombe (1989)

agreed with McGee (1979) who noted that training does not eliminate differences between

spatial ability of male and female students but rather improve scores of both male and female

students.

Improving Students’ Interest in the Study of Engineering Graphics with Computer

Technology

In any school setting, student’s motivation for learning is generally regarded as one of

the most critical determinants, if not the premier determinant, of the success and quality of

any learning outcome (Mitchell, 1992) High motivation and engagement in learning have

consistently been linked to increased levels of student success (Kushman, Sieber, and Harold,

2000). Development of academic intrinsic motivation in students is therefore an important

goal for educators because of its inherent importance for future motivation, as well as for

students effective school functioning. Motivation is the attribute that “moves” us to do or not

do something. According to Harter (1981) a student has an intrinsic orientation when

classroom learning is determined by internal interests such as mastery, curiosity, and

preference for challenge. Students who are more intrinsically than extrinsically motivated fare

better and students who are not motivated to engage in learning are unlikely to succeed

(Gottfried, 1990). Higher academic standards make it even more important to motivate even

the disengaged and discouraged learners (Brewster and Fager, 2000). Successful classroom

teachers are able to organize their classes and adjust their teaching strategies in a way that

motivates, engages, and challenges students to learn (Demmert, 2001). Students’ interest and

achievement in any learning activity is therefore, sustained by the active involvement of the

learner in all aspect of the learning process. Ogwo and Oranu (2006) and Ngwoke (2004)

emphasized that unless the teacher stimulates students’ interest in learning, students’

achievement will be minimal.

50

It has been established that the learner’s own feeling toward the subject matter will

largely determine how much of the material will be learned and how thoroughly it will be

learned. According to Ogwo and Oranu (2006) to facilitate learning, the teacher must secure

and sustain the attention and interest of the learner. They emphasized that unless attention is

maintained and interest sustained, learning can hardly be accomplished. A state of sustained

interest is shown by continued and determined readiness to learn on the part of the student as

evidenced by a state of readiness to learn.

Interest is a persisting tendency to pay attention and enjoy some activities. According

to Aiken (1979) an individual is interested in certain activities if he/she has preference for the

kinds of activities and things. Interest has been viewed as emotionally oriented behavioural

trait which determines a student’s vim and vigour in tackling educational programmes or other

activities (Chukwu, 2002). Interest, according to Hornby (2000) is an activity or subject that a

person enjoys and spends free time doing or studying. Interest belongs to the affective domain

of educational objective. Okoro (1994) noted that affective domain is concern with the

learners’ social development and the inculcation of new attitudes, values, and interest.

Ngwoke (2004) writing on the need to improve students’ interest in learning noted that

motivation is important in getting the learner absorbed in the task of learning. He maintained

that in getting the students to resist distractions, and to form favourable attitude toward

learning, interest, curiosity, and self- selected goals keep the learner at work without pressure

from the teacher. He explained further that a learner may have direct and indirect interest in a

learning task. A learner is directly interested if he desires to accomplish the task for his own

sake. He is indirectly interested if accomplishing the task leads to the attainment of something

else. Ngwoke however emphasized that direct interest increases the strength of ego-

involvement of the learner and does not allow the learner to be distracted by trivial extraneous

events in the perceptual environment. This means that when learners are involved in class

activities, learning is facilitated

The need to get students involved in the classroom learning activities has called for the

need for teacher to use teaching methods which are students-centred to minimize rote learning

and memorization of fact in the classroom. To facilitate students-centred instruction according

to UNESCO (2002) educational institutions need to embrace new technology and appropriate

computer technology as a learning tool to transform the present isolated, teacher-centered and

text bound classroom into rich, students-centred interactive knowledge environment.

Interestingly, providing opportunities to interact with course material through the use of

computers and information technology tends to change the course from a competitive

endeavour to one that is more collaborative, student-centred, and focused on the cognitive

51

development and construction of knowledge in the students (Brewer, 2003). Hence, one

means of constructing knowledge is to create meaning by doing. Creating support for

knowledge construction within the students is a critical component to the success of

developing self-motivated, intellectually stimulated learners (Osberg, Winn, Rose, Hollander,

Hoffman and Char, 1997). The obvious implication of the use of computer in the classroom

therefore, is to facilitate students’ interaction with the learning environment so as to sustain

students’ direct interest which increases the strength of ego-involvement of the learner and

which does not allow the learner to be distracted by trivial extraneous events in the perceptual

environment. Hence, to facilitate students’ interest in learning engineering graphics it is

important that computer technology such as AutoCAD designed for graphics construction

should be adopted.

Measurement of affective behaviour is currently receiving emphasis in Nigerian

schools. The Federal government of Nigeria (2004) gives two affective objectives of Nigeria

education. These are:

i. the inculcation of national consciousness and national unity,

ii. the inculcation of the right type of values and attitudes for the survival of

individual and Nigeria society

Hence, education should lead not only to the acquisition of cognitive knowledge and

psychomotor skills but also to the development of appropriate value and attitudes. Any

education that does not promote the right values, attitudes and interest to work, life and

society is of limited value. In order words, teaching of appropriate value, attitude and interest

should form part of every well organized educational programme.

Information of an individual interest can be obtained in various ways. The most direct

method that of simply asking people what they are interested in has its pitfalls. A person may

have little insight into what his or her interests are or what particular occupations are like.

Nevertheless, these expressed interests are sometimes better predictors than less directly

obtained information and should not be overlooked in education. Other methods of

determining interests are observing a person’s behaviour in various situations, inferring

interests from the person’s knowledge of special terminology or scores on other ability test,

and administering an interest inventory. The four methods-expressed interest, manifested

interest, tested interest and inventoried interest are applicable to the measurement of eight

basic interest groups defined by Super Crites in 1962 (Aiken, 1979). The eight groups

according him are scientific, social welfare, literary material systematic, contact, aesthetic

expression, and aesthetic interpretation. Aiken contended that, of the four methods, the

interest inventory has been the most widely used, not only does an interest inventory permits a

52

broader sampling of behaviours and preferences but it provides objective score for individual

and group comparison.

Computer Technology use for Teaching and Students’ Achievement

Students’ achievement connotes performance in school subjects as symbolized by a

mark or score on an achievement test. According to Epunam (1999) academic achievement of

student is defined as the learning outcomes of the students which include the knowledge,

skills and ideas acquired and retained through his course of study within and outside the

classroom situations. It is quantified by a measure of the student’s academic standing in

relation to those of other students of his age (Anene, 2005). Students’ achievement is

dependent upon several factors, among which are teachers’ qualifications (teachers’

experience and education), instructional methods and learning environment.

Teacher quality is a very important determinant of the quality of education. According

to Rivkin, Hanushek and Kain (2000) measurable characteristics of teachers such as teacher

experience, and education, explain variation in teacher effectiveness. Demmert (2001) opined

that solid content knowledge, sound pedagogy, outstanding interpersonal skills, understanding

of cognitive development and the different learning stages of students, are well-established

characteristics of effective teachers that produce greater students’ achievement.

Over the past decades, educational research has focused on the question of what

influences academic achievement or, more generally, what influences learning. Most studies

support theories that focus on the interaction between the student and the learning

environment. The interaction approach, assumes that academic achievement or learning is a

result of the complex interaction between the students and the learning environment.

Interaction is a more important facilitator of learning. Educational technologists have, of

course, always understood that a student must interact with an environment for learning to

occur (Winn, Hoffman, Hollander, Osberg, Rose and Char, 1997). Similarly, (Osberg, Winn,

Rose, Hollander, Hoffman and Char (1997) noted that interaction is a critical component to

students' knowledge construction. Brewer (2003) opined that computer-based technologies are

powerful pedagogical tools and can turn the passive students into an active participant in the

learning environment. According to UNESCO (2002) computer technology provides powerful

tools to support the shift to student-centred learning and is capable of creating a more

interactive and engaging learning environment for teachers and learners.

Computer enhances how students learn by supporting four fundamental characteristics

of learning: Active engagement, participation in groups, connections to real-world contexts,

53

frequent interaction and feedback (Basham, 2007). Strong and Smith (2001) stated that

human/computer interface has a direct relationship to stress on the user’s cognitive ability.

When designing instructional materials for computer use as well as subject matter mastery,

stress is reduced if a user can easily make use of the interface, comprehend the functions, and

use the tool to solve problems. Students must be able to easily navigate in a computer

environment in order to focus on the topic.

According to Cotton (2001) the use of computer based learning produces achievement

effects superior to those obtained with traditional instruction. Cotton explained further that

student learning rate is faster with computer based learning than with conventional instruction.

For instance, cotton noted that in some research studies, the students learned the same amount

of material in less time than the traditionally instructed students, besides, students receiving

computer-based learning learn better, faster and have more positive attitudes towards learning

than students receiving conventional. Other benefits of the computer based learning include:

Locus of control, Attendance, Motivation/time-on-task, and Cooperation/collaboration

Therefore, nowadays, it is a generally held position that the process of learning will

improve when learners are given computer-based learning that allow for interactive access

tuned to the specific needs of each individual learner. Computer artifacts for learning should

therefore be both interactive and articulated. Interactive learning environments can be seen as

engines for education that facilitate learning by having learners interact with a simulation of

the subject matter. AutoCAD which was used in this study to teach engineering graphics to

the National Diploma students has command prompt which provides human and computer

interface. The interface has been used in various studies and had been found to enhance

students’ interaction with computer technology when learning graphics.

Theoretical Framework:

Jerome Bruner’s Theory and the Use of AutoCAD for Improving Student’s Interest and

Achievement in Engineering Graphics

Bruner’s theory has four major principles (Nwachukwu, 1995). The first principle

deals with on motivation. The principle specifies the conditions that predispose an individual

towards learning. Implicit in the principle is the belief that almost all children have a built-in

“will to learn”. Bruner believes that reinforcement or external reward may be important for

initiating certain actions or for making sure they are repeated. But he insists that it is only

through intrinsic motivation that the will to learn is sustained. This is more important that the

more transitory effects of external motivation. The second principle deals with structure.

According to Bruner, the structure of anybody of knowledge can be characterized in three

54

ways: mode of presentation, economy and power. Mode of presentation refers to the

technique, the method whereby information is communicated. One of reasons teachers’

despair of trying to explain some fundamental point to a seemingly uncomprehending child is

that the teacher’s mode of presentation simply does not fit with the child’s level of experience.

Bruner believes that a person has three means of achieving understanding: enacting, iconic,

and symbolic representation. During each of these stages, a different mode of learning and

retention is used by the child. The third principle is sequence. Since Bruner believes that

intellectual development is innately sequential, moving form enacting, through iconic to

symbolic representation it is logical he also feels it is highly probable that this is also the best

sequence for any subject to take- wordless messages, speaking mainly to the learners’

muscular responses; then exploration of the use of diagrams and various pictorial

representations, and finally symbolic communication of the message through use of words.

This is the basic conservation approach. However, some children may be able to begin a new

area at the symbolic level, but then they need to be given the basic imagery to fall back on.

The forth principle has to do with reinforcement. To achieve mastery of a problem we must

receive feed back, knowledge of how we are doing. The reinforcement must also be in a form

the learners will understand. Ultimately, the learner must take a self-corrective function since

the ultimate aim of instruction is to make the learner a self problem solver

UNESCO (2002) summarized Bruner’s principles as follows (1) instruction must be

concerned with the experiences and contexts that make the student willing and able to learn

(readiness); (2) instruction must be structured so that the student can easily grasp it (spiral

organization); and, (3) instruction should be designed to facilitate extrapolation and/or fill in

the gaps (going beyond the information given). Implicit in Bruner’s theory is emphasis on

reinforcement and feed back to engage learners in the learning process in order to improve

achievement. According to Ngwoke (2004) feed back provides the learner with information

on progress made so far towards the goal of learning. He explained that feed back provides

information on the errors committed and what steps are to be taken to remedy the errors. Feed

back form the use of AutoCAD command which provide human and computer interface is

very closely related to the principle of reinforcement of Bruner. When learner invokes a

command in AutoCAD the learner receives feedback for AutoCAD. This exchange of

interaction between the learner and AutoCAD command engages the learner, improve interest

and achievement results.

55

Ausbel’s Subsumption Theory of Learning and the Use of AutoCAD for Improving

Students’ Achievement in Engineering Graphics

The American psychologist, David Paul Ausbel has made a particular study of

meaningful learning. He presents experimental evidence to suggest that it is easier to learn

material which can be related to existing cognitive structure than that which cannot. Learning

which can be so related is referred to as meaningful learning. Learning which cannot be

related to existing cognitive structure is often referred to as rote learning. Learning a concept

at the formal level entails meaningful reception learning as described by Ausbel (1963).

Ausbel defined cognitive structure of the individual as all the information that the individual

has about any particular area of experience. He further hypothesized that the cognitive

structure is organized in a hierarchical fashion with the most generalized principles or concept

at the core round which are organized this successively more specific concepts and units of

information. This interpretation of the organization of knowledge stored in the secondary

memory appears to be generally accepted for semantic content. The memory field or location

for semantic content is called semantic memory.

Textbooks, reference works, sound, films and other instructional materials are used

extensively to teach concepts. When students study the new materials presented, relate the

new information to what they already know, and organize it into a more complete cognitive

structure, they are engaging in meaningful reception learning according to Ausbel’s theory

(Ausbel, 1963). Implicit from the Ausbel’s theory is ‘sub-sumption model’ which advocates

for “meaningful” as opposed to “rote learning”. Meaningful learning occurs when there is an

interaction between the students’ appropriate elements in knowledge that already exist and the

new materials to be learnt. However, where such interaction does not take place, rote learning

occurs. Those parts of the learner’s cognitive structure (organization of knowledge) which can

provide for the interaction necessary for meaningful learning are called “subsumers”. A

subsumer is a principle or a generalized body of knowledge that the learner already acquired

that can provide for association or “anchorage for the various components of the new

knowledge, while subsumption model is an instructional device in which central and highly

unifying ideas are stated in terms already familiar to the learner, to which he can meaningfully

relate new learning materials by subsumption. This theory is much related to the use of

AutoCAD for providing students’ interaction with the learning environment. When learners

are engaged in their learning with AutoCAD meaningful learning occur through interaction

between the learners and the new materials to be learnt.

56

Cognitive Interaction Learning Theory and Development of Spatial Ability

Cognitive Interaction learning theories is a means of understanding the learning

process for obtaining and improving the spatial ability. The cognitive interaction learning

theory and experiential learning theory are very closely related. The interactive exchange of

action and feed back from the computer provides a constant learning environment.

The cognitive interaction learning theories assert that learning occurs when cognitive

function interacts with the meaningful psychological environment around it. There are two

forms of cognitive interaction theories namely: linear and field (Bandura, 1993).The linear

and field forms of the cognitive interaction theory are very similar in nature. The linear form

of cognitive interaction belief that perception and behavioral changes (learning) occur in

sequence; while the field version of cognitive interaction states that there is a simultaneous

interaction occurring between the learner and their psychological environment (Bigge and

Shermis, 1998). This theory could explain the phenomena of the quick learning that children

exhibit with video games. The theory indicates that the learner actually learns by doing and

adapting to new conditions and perceptions. The same conditions would apply to the learner

using Computer animation and solid model in a virtual environment provided with AutoCAD.

Learning by doing provides the interaction that is present in the interaction learning

theory. As shown in the Figure 16 below, if the learner is able to interact with the computer

animation and solid model environment, then according to the cognitive interaction theory by

extrapolation the learner should be able to improve depth perception and increases conceptual

ideas through the development of mental models which in turn improve his/her spatial ability.

The interaction between the learner and the animation provide immediate information to each

other. When the learner provides commands to control the animation, the animation provides

the learner with immediate feedback allowing the learner to see the results of his actions. The

learner is then able to gain knowledge through experience. The function of the teacher in this

model is to help control the learning situation and to act as a learning model for the student.

The teacher is able to evaluate the action/reaction of the learner and provide the necessary

stimulus for the continued education experience of the learner.

57

Figure 16: Interaction between the learner and the computer environment for developing

spatial ability

Piaget's Theory of Cognitive Development and Spatial Ability Development

The developmental psychology of Jean Piaget recognizes the active role of both

individual and his environment in the learning process. According to Nwachukwu (1995)

Piaget observed that a child passes through distinct stages of mental growth, in the process of

growing up to maturity. These developmental stages are; Sensorimotor period (years 0–2),

Preoperational period (years 2–7), Concrete operational period (years 7–11), and Formal

operational period (years 11–adulthood).

The Sensorimotor period marks the development of essential spatial abilities and

understanding of the world. The term ‘sensory’ refers to the information a child obtain

entirely through the sense organ while the term ‘motor’ refers to child bodily activity,

grasping, kicking, manipulating, e.t.c. This period is when Piaget thought that a child begins

simple repeated reflex exercises, such as grasping (Baskovich, 2001). After about a month

(these time periods can vary with environment), the infant shows his first acquired

adaptations, and can repeat and reverse successful actions in well-defined sequences. In half a

year the infant begins to understand causality; he can interact with his environment to bring

about a desired change. While at first the change is immediate, soon after he can work

towards and expect a delayed result. At this time, he can also associate an object with its

spatial position, looking for something where it was last seen. At about two years, he begins

58

to experiment, repeating actions with slight variations to test the different effects. Problems

are more easily solved, space and causation are better understood, and memory is improved.

Finally, he obtains the ability to evoke schemas mentally, facing problems with immediate

solutions. Thus, the sensorymotor period is a period when a child develops object

permanence, and beginning of symbolic representation (Ugwoke and Eze, 2004; Munro,

1999).

The Preoperational period is the second of four stages of cognitive development. By

the word ‘operations’ Piaget means complex mental activities. Children are not capable of

these operations in this age group and so the period is called pre-operational (Nwachukwu,

1995). According to Baskovich (2001) by observing sequences of play, Piaget was able to

demonstrate that towards the end of the second year a qualitatively new kind of psychological

functioning occurs. (Pre)Operatory thought in Piagetian theory is any procedure for mentally

acting on objects. The hallmark of the pre-operational stage is sparse and logically inadequate

mental operations. During this stage the child learns to use and to represent objects by images

and words. In other words they learn to use symbolic thinking. Thinking is still egocentric:

The child has difficulty taking the viewpoint of others. The child can classify objects by a

single feature: e.g. groups together objects regardless of shape or all regardless of color. As

aids during this stage, objects of various sizes are important for space, construction, and

counting, as well as water, sand, and bricks (or objects with similar properties); and paint for

the advancement of representation, which is later important to internalization, representing

objects with other objects and symbols. They begin representing things with words and

images. However, they still use intuitive rather than logical reasoning. Children have highly

imaginative minds at this time and actually assign emotions to inanimate objects.

The Concrete operational period is the third of four stages of cognitive development in

Piaget's theory. This stage, which follows the Pre-operational stage, occurs between the ages

of 6 and 12 years and is characterized by the appropriate use of logic. The word ‘operation’

means mental action that can be reversed. Piaget defines ‘operation as an action which can

return to its starting point and which can be integrated with other actions also possessing this

feature of reversibility; it gets the term ‘concrete’ because the starting point for the action is

always some real system of objects and relations that a child perceives (Nwachukwu, 1995).

He explained further that the noticeable accomplishments of this period include; Seriation—

the ability to sort objects in an order according to size, shape, or any other characteristic. For

example, if given different-shaded objects they may make a color gradient. Classification—

the ability to name and identify sets of objects according to appearance, size or other

characteristic, including the idea that one set of objects can include another.. Decentering—

59

the child takes into account multiple aspects of a problem to solve it. For example, the child

will no longer perceive an exceptionally wide but short cup to contain less than a normally-

wide, taller cup. Reversibility—where the child understands that numbers or objects can be

changed, then returned to their original state. Conservation—understanding that quantity,

length or number of items is unrelated to the arrangement or appearance of the object or items.

For instance, when a child is presented with two equally-sized, full cups they will be able to

discern that if water is transferred to a pitcher it will conserve the quantity and be equal to the

other filled cup. Elimination of Egocentrism—the ability to view things from another's

perspective.

The formal operational period is the fourth and final of the periods of cognitive

development in Piaget's theory. This stage, which follows the Concrete Operational stage,

commences at around 11 years of age (puberty) and continues into adulthood. It is

characterized by acquisition of the ability to think abstractly, reason logically and draw

conclusions from the information available (Munro, 1999). It is at this stage Piaget noted that

the child develops concept of space, and that topological notions such as proximity,

separation, order, enclosure and continuity arise first, Projective and Euclidean notions arise

later. According to Nwachukwu (1995) topology concerned with geometrical properties

unaffected by changes of shape or size. Projective properties of a figure are those that are not

changed if the figure is projected onto any plane surface as when it casts a shadow. And

Euclidean properties are those actual lengths and measurements of a figure constant, as when

a figure is merely translated or copied in another spot

The obvious implication of Piaget’s theory is that the acquisition of spatial concepts is

an essential aspect of human development and has a relationship with age. Also the theory

placed emphasis on the fact that spatial knowledge is developed as human beings interact with

objects in their environment. There are as well other key aspects of this development of

spatial knowledge. First, the distinction is made between the perception and representation of

spatial knowledge. Perception is the knowledge of objects that one obtains as a result of direct

interaction with them. This begins when children first become interested in their world during

the sensorimotor stage. Representation refers to the child's capacity to reason about the spatial

properties of an object when it is no longer present and to think about spatial concepts without

reference back to specific objects. This was seen as a form of mental imagery and was

believed to begin to develop towards the end of the sensorimotor stage (around the age of

two) and becomes refined towards the beginning of the concrete-operational stage. A second

aspect of Piaget's theory is the distinction made between two components of thought; the

figural and the operative. The figurative aspect refers to fixed states; the child describes the

60

spatial concept the way it is experienced. The operative aspects refer to mental operations that

the child may apply to a spatial concept, for example, transforming between different states of

a concept, predicting outcomes of an intended transformation. A child who can see a square

and names it is using figurative knowledge. A child who can reason that the outcome of

rotating a square would be a diamond is using operative knowledge.

Need Achievement Theory of Motivation and the Use of Computer Technology for

Stimulating Students’ Interest in Learning

Motivation has been defined as the level of effort an individual is wiling to expend

toward the achievement of a certain goal. Biehler and Snowman (1993) stated that motivation

is typically defined as the forces that account for the arousal, selection, direction, and

continuation of behaviour. According to Nwachukwu (1995) motivation refers to all those

phenomena which are involved in the stimulation of action towards particular objectives

where previously there was little or no movement towards those goals. Both definitions imply

that motivation comes from within a person. Therefore, teachers’ responsibility is to create

learning environment that will enhance students’ motivation to pursue academic goals actively

over a long period of time.

The need achievement motivation theory rests on the belief that most persons want to

achieve and experience levels of aspiration in a given environment. Contributors of

achievement motivation theory are John W, Atkinson and David McClelland. According to

Atkinson when an individual is actively involved on a task, he sets himself a standard to

conquer (Ngwoke, 2004). This standard is called the level of aspiration. Nwachukwu (1995)

pointed out that level of aspiration is a longing for what is above one, with advancement as its

goal. Aspiration has to do with the desire to improve or to rise above one’s present status.

There are two set of factors which interacts to determine the level of aspiration. They are the

personal factors and the cultural factor/environmental factors. Ngwoke explained that personal

factor relate to such personality traits as intelligence, interest, gender, self concept, activity

level, socio-economic status and previous training experience. Cultural and environmental

factors include parental ambition, social values and social reinforcement. Need achievement

is more influenced by environmental factors. Some environmental factors encourage the

development of immediate aspiration.

According to Ngwoke (2004) the implication of need achievement theory is that the

teacher should create learning environment conditions that will help learners adequately

assess their abilities and opportunities available so that they can set realistic and attainable

goals. In this way learners will experience success in school activities and thereby build

61

positive self-concept which enhances need achievement motive. Owing to the dominance of

the teacher in the traditional teaching approaches, students are not engaged in the classroom

activities because such environment is not provided. This results into rote learning and

memorization of facts with little transfer of knowledge. Opara (2002) observed that the

method hardly increased students’ enthusiasm and interest. Teaching methods based on

cognitive learning theory such as use of computer technology provides students’ interaction

with the learning environment which invariably provides meaningful learning activities.

Meaningful learning activities built on prior knowledge motivate students and foster their

interest in their effort to executively control their own cognitive process.

Review of Related Empirical Studies

A number of studies had been conducted on the effects of Computer-Aided Design

software packages on students’ spatial ability and Achievement in various disciplines and on

the effects of spatial ability on gender. Hence, the review of related empirical studies in this

study is organized under two sub-headings, namely; Studies on the Effects of Computer-

Aided Design (CAD) Packages on students spatial Ability and Achievement, and studies on

the Effects of Gender on Spatial Ability.

Studies on the Effects of Computer-Aided Design (CAD) Packages on students

spatial Ability and Achievement

Rafi, Samsudin, and Said (2008) conducted a study on training in spatial visualization:

the effects of training method and gender. A class of technical education program comprising

thirty-three secondary school pupils (13 girls and 20 boys, mean age = 15.5 years) of SMK,

Kuala Kubu, Selangor, Malaysia volunteered to participate in this experimental study.

Stratified sampling rather than simple random sampling was used as the sample did not have

equal number of genders where the student class comprised approximately 40% girls and 60%

boys. Proportionate allocation technique ensured that randomized assignment of students into

groups would reflect the same male and female strata. Three groups were formed namely two

experimental groups and one control group. The first experimental group (4 girls and 7 boys)

trained in the interaction-enabled desktop virtual environment (i-DVEST), the second

experimental group (4 girls and 7 boys) received training in animation-enhanced desktop

virtual environment (a-DVEST), and the control group (5 girls and 6 boys) was exposed to

conventional training. A multi-factorial pretest posttest design procedure was used and data

were analyzed using 2-way ANCOVA. Spatial visualization training in interaction-enabled

desktop virtual environment (i-DVEST) was the most effective where the participants had

62

made substantial improvement. Interactions with the virtual objects provides better visual

perception of spatial arrangements of the spatial tasks that leads to better visualization

especially for boys. Animation-enhanced desktop virtual environment (a-DVEST) training

was the second most effective in spatial visualization. Animations of the tasks provided the

perceptual cues of the spatial arrangements of the spatial problems leading to improved

visualization. Both genders benefited in this training setting indicating that animation helped

minimize the cognitive effort to visualize the spatial tasks. Training with animation-enhanced

desktop virtual environment (a-DVEST) seemed less cognitively challenging than the

interaction-enabled desktop virtual environment (i-DVEST) method of training. Conventional

training relying on printed materials was least effective among the three methods of training.

Poor representation of training objects of 3-D into 2-D format minimizes cognitive

correspondence between the two representational methods hindering visualization of the

spatial tasks. Like AutoCAD, the i-DVEST and a-DVEST developed by the researchers to

conduct the study have animation and are also capable of virtual reality, all of which are found

effective for visio-spatial learning.

Basham (2007) conducted a study on the effects of 3-Dimensional CADD modeling

software on the development of spatial ability of ninth grade technology discovery students.

The study utilized Pro/Desktop 3-D CAD Modeling software. The subjects of the study were

ninth grade technology discovery students in Mississippi schools operating on a 4 x 4 block

schedule during either fall or spring semesters in the 2005-2006 school year. Three intact

classes which were taught with different methods were selected for the study. Pretest posttest

quasi-experimental research design was used for conducting the study. Mean and standard

deviation were used to answer the research questions while ANCOVA was used to test the

hypotheses formulated for the study. The study found out among others that there is a

difference in spatial ability based on the method used to instruct the students. Also a

statistically significant difference existed concerning the method used to instruct students on

the use of 3-D CADD modeling software. The instruction consisting of method of teacher-led

instruction using the 3-D CADD modeling software in a design lesson, followed by student-

directed modular instruction using the 3-D CADD modeling software, were found to be

effective in improving spatial ability of the students. The groups of student taught using 3-D

CADD modeling software methods had higher mean posttest scores than students instructed

with demonstration methods. The demonstration methods did not significantly affect student

achievement on the test of spatial ability. According to the researcher, the choice of 3-D

CADD modeling software was based on the fact that in Mississippi schools 2-D CADD

software packages were predominantly used to teach computer-aided design to the technology

63

discovery students even though 3-D CADD packages had been in existence. The researcher

was of the view that there was a need to test the effectiveness of 3-D CADD packages on

students’ development of spatial ability. The implication of this study to the present study is

that it showed that 3-D CADD software is effective in improving students’ spatial ability in

the graphics. It further affirmed other scholars’ findings that demonstration method of

instruction in teaching graphics does not improve the spatial ability of the students. AutoCAD

is capable of drawing in 3-D like Pro/desktop 3-D CADD software that was used in the study.

Asilokun (2006) conducted a study on the effects of AutoCAD on the performance of

secondary schools students in technical drawing in Lagos state. The study was a posttest only

control group design. The experimental group was taught with AutoCAD two-dimensional

technique while the control group was taught with traditional drafting technique of

demonstration and drawing instruments on the chalkboard. Mean and standard deviation was

used to answer the research question while t-test statistics was used to test the hypothesis. The

study found out that students taught technical drawing with AutoCAD performed better than

those taught with traditional drafting technique of demonstration and drawing instruments on

the chalkboard and the effect was found to be significant. Hence, the study recommended

among others that government should equip all technical and secondary schools with adequate

computer for the adoption of AutoCAD in the teaching of technical drawing in the secondary

schools.

Koch (2006) conducted a study on the effect of solid modeling and visualization on

technical problem solving. This research was undertaken to investigate the effects of solid

modeling and visualization on technical problem solving. The participants were 47 students

enrolled in solid modeling classes at Southeast Missouri State University. The control and

experimental groups consisted of 23 and 24 randomly assigned students respectively. This

study was a posttest only design that used logistic regression to analyze the results. Both

groups were required to take the Purdue Spatial-Visualization Test/Visualization of Rotations

(PSVT/TR). Participants in the control group used only sketching to design their solutions

while participants in the experimental group used Pro/Desktop 3-D CADD parametric solid

modeling software capable of animation, virtual reality and solid modeling to design their

solutions. All participants then constructed prototypes of their designs. The prototype was

evaluated to determine if it successfully met the design specifications. The findings revealed

that visualization was a significant predictor of technical problem solving as defined by

successful prototype construction. There was no significant difference between the sketching

and solid modeling design methods used for technical problem solving. The interaction

between the method of design, solid modeling or sketching, was analyzed to determine if

64

using solid modeling would offset low visualization scores. It was found that the interaction

was not significant. Animation, virtual reality and solid modeling were used as the elements in

the Pro/Desktop 3-D CADD parametric solid modeling software to improve students’ spatial

ability. AutoCAD, which is used in the present study also capable of animation, virtual reality

and solid modeling as elements for improving spatial ability

Scribner and Anderson (2005) conducted a study on influence of instructional methods

and individual learning styles on novice drafter’s spatial visualization development.

Nonequivalent control group quasi-experimental research design was used to conduct the

study. This study took place during the fall of 2003 and the spring of 2004 and consisted of 49

full- and part-time community college students who volunteered to participate. All subjects

were enrolled in either basic drafting or engineering graphics courses, which were offered

once a semester at an Illinois community college. The experimental group consisted of 23

students, of which 11 students enrolled in the basic drafting course in the fall 2003 semester

and 17 students enrolled in the engineering graphics during the spring semester of 2004. The

control group consisted of 26, of which 19 students enrolled in the engineering graphics

course during the fall semester of 2003 and 11 students enrolled in the basic drafting course in

the spring of 2004. The students in the classes comprising the control group were instructed

using traditional methods of lecture and demonstration on paper or white board. The

experimental group received additional instruction that included methods appealing to the

seven learning styles addressed in the Perceptual Modality Preference Survey (PMPS)

developed by C. Edward Cherry (Harvey, 2002). Instruction for the experimental group used

Auto Desk AutoCAD 2002 computer-aided drafting software. The experimental group’s

instruction incorporated PowerPoint presentations, class discussion, computer-based

instruction, and group projects to aid the aural and interactive learners. To accommodate

learners with visual and print learning styles, the instructor incorporated orthographic

sketches; multiview, oblique, and isometric projections; as well as textbook readings, chapter

outlines, class handouts, and workbook modules for spatial visualization. The instructor made

use of three-dimensional physical objects to aid haptic or kinesthetic learners. A teaching

method that addressed the olfactory learning style was not used in this study due to the

unavailability of three-dimensional objects that could be used. The study revealed that a

statistically significant difference existed between novice drafters’ spatial visualization ability

scores as measured on the Purdue Spatial Visualization Test (PSVT) and the instructional

methods used by their instructors in favour of the experimental group, also, a statistically

significant relationship did exist between novice drafters’ spatial ability posttest scores on the

Developments section of the PSVT and posttest “aural”, pretest “interact”, and posttest “print”

65

learning styles as assessed on the Perceptual Modality Preference Survey (PMPS). In addition,

a negative relationship was found between posttest scores on the Developments section of the

PSVT and pretest “olfactory” learning style on the PMPS. The implication of this study to the

present study is that AutoCAD enhances spatial ability development compare to the

demonstration method of teaching engineering graphics.

Hart (2003) conducted a study on the effects of computer animation instruction on

spatial visualization performance. The purpose of this study was to determine whether

instruction in technical animation improves spatial visualization in undergraduate students

more than instruction in technical graphics without animation. A sample of 31 students was

used as a control and experimental group. The treatment for group 1 (experimental) was the

normal course work and instruction in three different animation packages. The instruction

included the history, terms and techniques used in animation. Instruction in Flash ® (a two-

dimensional animation package), TrueSpace ® (a three-dimensional gaming animation

package), and 3D Studios Max ® (a professional quality animation package) was also

provided. The students were required to complete a project using each of the animation

packages. The projects consisted of simple animation actions for Flash ®, an animation of a

cross sectional view of an internal combustion engine. In TrueSpace ®, objects were required

to roll off a table top and bounce realistically on the floor. Primary emphasis was placed on

3D Studio Max ® in which the students were required to create a one minute animation on

any technical subject of their choosing. The treatment provided to group 2 (control) was that

of the normal instruction and assignments for the Foundations of Graphics classes. Instruction

included the topics of sketching, geometric relationships, multiview sketching, isometric

sketching, dimensioning practices, and section and auxiliary views. Instruction in AutoCAD

® was also provided to acquaint the students with CAD applications. The students in group 2

were required to learn how to use the AutoCAD ® program by completing provided tutorials

and completing two major projects that allowed the students to demonstrate their competency

in technical graphic fundamentals and AutoCAD ®. The spatial visualization performance of

the students in the animation group was compared to control group of the students in a

foundation of graphics class. The study found out that the students in the animation group did

not significantly improve their spatial visualization. Also, The students in the technical

graphics class did not significantly improve their spatial visualization A possible explanation

for the lack of significant improvement is that the spatial visualization of the students had

previously developed and that no further improvement in scores could be measured with the

Purdue Visualization of Rotations Test. Hart explained that the lack of significant difference

in spatial visualization performance between the test groups is surprising because it had been

66

noted that animation should improve spatial visualization performance. The study utilized

AutoCAD without animation for the control group while the experimental group was taught

with package such as Flash, True space, and 3D studios max with animation. The implication

of the study to this present study is that AutoCAD as the time it was a 2-D CAD package

without animation it was capable of improving students’ spatial visualization like any other

animation packages.

Baldwin and Hall-Wallance (2001) conducted a study on the spatial ability

development in the geosciences. The study was conducted using pretest posttest quasi-

experimental research design. Mean, standard deviation, t-test and one-way Analysis of

Variance was used in the data analysis. The study was designed to evaluate change in

students’ spatial skills as a result of specific interventions using CADD software packages.

The test subjects included high school students in earth science classes, college level non-

science majors enrolled in a large enrollment introductory geoscience courses and

introductory level geoscience students. All students completed spatial tests to measure their

ability to mentally rotate three-dimensional objects and to construct a three-dimensional

object from a two-dimensional representation. Results showed a steady improvement in

spatial skills for all groups. It was also indicate that students choosing science majors typically

have much higher spatial skills as they enter college. Specific interventions to improve spatial

skills included having a subgroup of the non-science majors and high school students

complete a suite of Geographic Information System (GIS) activities. The intervention at the

high school level was more extensive and resulted in significant improvements in both

categories of spatial ability. At the college level, the non-science majors that received the

intervention showed no significant difference from those that did not, probably because the

time spent on the intervention was too short. The geoscience majors had nearly three times the

improvement of non-science majors in both categories of spatial ability attributed to hands-on

weekly laboratory experiences. These result revealed a wide range of abilities among all

groups of students, and suggest that teachers should evaluate teaching strategies in all courses

to ensure that students can interpret and understand the visual imagery used in lectures.

Lemut, Pedemonte and Robotti (2000) conducted a study on the effect of AutoCAD on

the geometric knowledge of fine arts high school students in Italy. This research was

undertaken to find out the potential that AutoCAD offers for the conceptualization f geometric

construction as an approach to theoretical knowledge. The participants were 10th grade

students (mean age= 15years) at a fine arts high school. This study was a posttest only design

that used mean to answer the research questions and ANCOVA to test the hypotheses

formulated for the study. Under teacher guidance, the treatment group was made to construct

67

different types of virtual geometric models of real objects using AutoCAD and convert it to

two-dimensional form of the models, while the control group was taught using the traditional

drafting method. The study found out that the treatment group achieved a statistical significant

gain compared to the control group. It was concluded among others that, under teacher

guidance, constructing objects in AutoCAD favour a deeper understanding of the meaning of

geometric construction in that during the geometric construction process with AutoCAD

students have to think about definitions, properties of geometric figures and geometric

relationships because construction strategies in AutoCAD are not free as in the pen-and –

paper environment, but are guided by the system’s request appearing on the command prompt.

This study found out that the use of AutoCAD is effective than the traditional method in

teaching geometric construction. The present study investigated effects of AutoCAD on

National diploma students’ spatial ability interest and achievement in engineering graphics.

Engineering graphics also deals with Geometric construction. Hence, the implication of the

study to this present study is that AutoCAD is effective in teaching engineering graphics than

the traditional drafting technique.

Winn, Hoffman, Hollander, Osberg, Rose, and Char (1997) conducted a study on the

effect of student construction of virtual environment on the performance of high- and low-

ability students in Washington. The main purpose of this study was to test the hypothesis that

the unique experiences of building and visiting Virtual environments would be more useful to

students than Learning in "traditional" classrooms. The study therefore examined the extent to

which students' general ability, and secondary school students' spatial reasoning ability and

spatial orientation ability predicted performance after learning by building and visiting Virtual

environments and after learning the same content in more traditional ways. Also, because

earlier observations had suggested that gender might also interact with spatial ability to

predict performance, the study looked for gender differences in spatial ability. A posttest only

control group design was adopted for the study. 3-D CAD software package was used for the

development virtual environment. Three hundred and sixty-five students from grades 4 to 12

participated in the study.

A four-step approach to constructing Virtual environments: Planning, modeling,

programming and experiencing were employed. The entire process took from six to ten weeks

with numerous visits by project staff to the students and their teachers, with, again,

considerable variability form school to school. During the planning phase, students worked in

groups to make decisions about how the VE should look and behave. They were given the

task of constructing a VE in which other students could learn the content they were studying.

This required them to find ways to show objects and to design metaphors for invisible objects

68

and procedures. Modeling required the students both to learn the 3D CAD software we used

for the project, running on Macintoshes in their classrooms, to design their objects on paper

and then to draw them in three dimensions on the computer. Programming was conducted by

laboratory staff. This involved assembling the objects into the Virtual environment, following

the students' instructions, and imbuing the Virtual environment with the intended behaviors.

For the experiencing phase, students visited the Virtual environments they had created. They

were given specific tasks to perform. After performing these tasks, which took from ten to

fifteen minutes, students completed knowledge posttests and the general and spatial ability

tests, and completed a questionnaire. The study revealed that there was no main effect for

group. However, the interaction of group with ability was significant. Low-ability students

who did world-building significantly outperformed those studying in the traditional way. For

high-ability students, there was no difference in performance of the experimental and control

groups. Students were also blocked on their spatial ability and spatial visualization scores. No

significant main effects or interactions were found for either measure with content posttest

performance as the dependent variable. This study tested the effects of virtual reality on

students’ spatial ability. AutoCAD also capable of providing students with tools for

developing virtual objects, and interact with the objects in a virtual environment.

Studies on Effects of Gender on Spatial Ability

Nemeth and Hoffmann (2006) conducted a study on gender differences in spatial

visualization among engineering students. A pretest posttest non-randomized control group

quasi-experimental research design was used. Specifically, the study was designed to present

an analysis of a Mental Cutting Test (MCT) of first year engineering students, with special

emphasis on gender differences. The MCT is one of the most widely used evaluation method

for spatial abilities. Mean, standard deviation and ANCOVA were used in the data analysis of

the study. The result of the study showed that male performed better than female in the spatial

ability test. Similar to other international projects, significant difference was observed

between male and female scores. The study conducted by the researcher supports the fact that

there is a difference in the spatial ability of male and female engineering students. One of the

independent variable whose effect was determined on spatial ability in this present study is

gender.

A study conducted by Medina, Gerson and Sorby (2000) examined gender differences

in the 3-D Visualization skills of engineering students in Brazil and in the United States. Two

universities were selected for the study, namely: The Maua Engineering School and Michigan

Technology University. The study is a pre and posttest quasi-experimental design. Mean and

69

standard deviation and ANCOVA were used for data analysis. The study revealed that the 3-D

spatial visualization of skills of female students lag behind those of their male counterparts.

The analysis also showed that there is a certain group of students whose spatial visualization

skills was not significantly improved after a full year of graphics instruction. For these

students, the traditional graphics courses are a source of frustration, since they typically have

very weak visualization skills from the outset. The study recommended that in order to help

these students attain a minimum proficiency in their spatial skills so that they can then

actively participate in a traditional graphics course, a new techniques must be developed

which take into account their particular deficiency. The study showed that there is a difference

in spatial ability of male and female engineering students in Brazil. The present study

determined the effects of gender on spatial ability of male and female National diploma in

mechanical engineering technology students in Nigeria

Burin, Delgado and Prieto (2000) conducted a study on solution strategies and gender

differences in spatial visualization tasks. The study was a pretest posttest quasi-experimental

research design. Mean, standard deviation and ANCOVA were employed in the data analysis.

Two kinds of strategies, analytic and holistic or spatial manipulation, were operationalized by

a self-report questionnaire and three time based variables obtained in a computerized form

board task, the R-E. The computerized R-E was administered in a Machintosh LCII computer.

It consist of 36 items in which the examinee must decide if a target figure can be formed out

of a set of figure that are supposedly part of the target one. The variables were: time of initial

encoding of the target stimulus, duration of processes that follow the first encoding, including

visual comparisons and mental movement, and total time for each item. 75 women and 77

men completed the visualization tests, the R-E and the self-report measure. The study

revealed that neither level of visualization in maker test nor gender were associated with

strategy choice. Given gender differences in spatial ability the aim of the researcher was to

determine strategies used by male and female to solve spatial tasks.

In another study, Branoff (1998) conducted a study to determine the effectiveness of

adding coordinate axes to a mental rotations task. Eighty-one under graduate students enrolled

in introductory graphics communication courses completed a computer version of the Purdue

Visualization of Rotations Test (PVRT). The instrument was used to record students’

responses and response times as well as information on gender, current major, number of

previous graphics courses completed and method used to solve the test items. Coordinate axes

were added to a portion of the PVRT for the experimental group to determine if the axes

provided contextual cues necessary to improve sores and response times. The researcher

hypothesized that coordinate axes would provide verbal cues that could be coded along with

70

nonverbal information to improve mental rotation efficiency. The additional coordinate axes

slightly (but not significantly) improved scores on the PVRT, but not response times. Also,

the addition of axes eliminated gender differences on the experimental group. The study

affirmed the benefit of coordinate axes in improving students’ spatial ability. Drawing in

AutoCAD environment involves the use 2-D coordinate and 3-D Cartesian coordinate. The

present study tested the effects of using 2-D and 3-D Cartesian coordinate on students’ spatial

ability, interest and achievement in engineering graphics.

Summary of the Reviewed Related Literature

Technology developments have created changes in all aspects of society. Therefore,

educational systems around the world are under increasing pressure to use computer

technology to teach students the knowledge and skills they need to function effectively in the

world of work. Computer technology provides powerful tools to support the shift to student-

centred learning and is capable of creating a more interactive and engaging learning

environment which stimulates learners’ interest and improves achievement in learning. Hence,

it is a generally held position that students’ achievement in learning will improve when they

are given computer-based learning that allow for interactive access.

AutoCAD is one of the interactive Computer-Aided Design software packages

developed by Autodesk for graphics design such as engineering graphics. The review of

literature has shown that the need to use computer technology for teaching, couple with the

recent attention to spatial ability in engineering graphics due to vast changes in computer

technology have necessitated researches on effects of Computer-Aided Design (CAD)

software packages on students achievement and spatial ability in graphics in various

disciplines. Numerous studies have been conducted to identify techniques that will enhance

the development of spatial ability in students with the use of CAD packages. Several studies

had compared the effectiveness of instruction using AutoCAD with other CAD software

packages and have found out that AutoCAD is effective for improving student achievement

and spatial ability. Also some study reviewed had compared AutoCAD with traditional

drafting method and found out that AutoCAD is more effective than the traditional drafting

method in teaching graphics. Further more, several studies had compared instructional design

with animation and virtual reality using CAD Packages and had found out that instructional

design with animation and virtual reality with CAD packages are effective in improving

students’ spatial ability than printed material on papers. Generally, most of the studies had

found out that AutoCAD and other CAD software packages are effective in the improvement

of students’ achievement and spatial ability in geometric construction. Literature also showed

71

that the major elements responsible for the effects of AutoCAD and other CAD software on

students’ achievement and spatial ability are the use of command prompt that provides human

and computer interface which enhances student’s interaction with the learning environment,

use of Cartesian coordinate system, animation, virtual reality and solid modelling which are

capable of improving spatial visualization.

Given the effectiveness of AutoCAD and other CAD software packages in the

teaching of graphics, several disciplines all over the world, have adopted the use of CAD

software packages for teaching aimed at improving students achievement and spatial ability.

However, demonstration with drawing instrument on the chalkboard is predominantly used to

teach engineering graphics to the National diploma students in Nigeria Polytechnics in spite of

the fact that the language of engineering graphics design in the world of work nowadays is

Computer-Aided Design (CAD). CAD packages available in the market are either 2-D or 3-D

software packages. 2-D CAD software is capable of drawing with two-dimensional coordinate

only, while most 3-D CAD software is capable of drawing with both two-and three-

dimensional coordinate. The review of literature revealed that before the advent of Release 10

version of AutoCAD, it was a fully self-contained two-dimensional CAD software. The

advent of Release 10 capable of 3-D marked a remarkable turning point in AutoCAD

techniques and applications and makes AutoCAD one of the most powerful CAD software

packages popularly known and use in the industry. AutoCAD became capable of both two-

and three- dimensional coordinate for graphics. When drawing with 3-D techniques in

AutoCAD environment user no longer deals with only x and y coordinate, but also with the z

axis as well. Thus, drawing with 2-D techniques is different from drawing with 3-D technique

in AutoCAD environment. This difference perhaps may produce different effects on students’

achievement, interest and spatial ability in learning engineering graphics. There was no

literature on the effects of AutoCAD 2-D and 3-D techniques on the spatial ability, interest

and achievement of National Diploma students in engineering graphics in Nigeria. It becomes

expedient to ask: which of the techniques of AutoCAD (2-D or 3-D) would improve students’

spatial ability, interest and achievement in engineering graphics? Hence, this study sought to

experimentally investigate the comparative effects of two and three dimensional techniques of

AutoCAD on National Diploma students’ spatial ability, interest and achievement in

engineering graphics.

72

CHAPTER III

METHODOLOGY

This chapter presents the procedure used to carry out this study under the following

sub-headings; design of the study; area of the study, population for the study; sample and

sampling technique; instrument for data collection; validation of instruments; reliability of

instruments; experimental procedure; method of data collection; and method of data analysis.

Design of the Study

A quasi-experimental design was used in this study. Specifically, the pretest, posttest,

non-equivalent control group design was adopted for the study. According to Gall, Gall and

Borg (2007) quasi-experimental design can be used when it is not possible for the researcher

to randomly sample the subject and assign them to treatment groups without disrupting the

academic programmes of the schools involved in the study. This design was considered

suitable to conduct this study because intact classes (non-randomized groups) were assigned

to the two different techniques of AutoCAD (2-D and 3-D techniques) in order to determine

comparative effects of the AutoCAD techniques on National Diploma student’s spatial ability

interest and achievement in engineering graphics. The design is represented below.

Furthermore, in the analysis, 2×2 factorial design was adopted to present the treatments

(AutoCAD 2-D and 3-D) at two levels and Gender (male and female) at two levels. Hence,

the research was able to assess the effect of the main independent variables (AutoCAD 2-D

and 3-D) as well as the effects of moderator variable (Gender- Male and Female) on spatial

ability, interest and achievement of National Diploma students in engineering graphics.

Group A: O1 X1 O2,

Group B: O1 X2 O2,

Where; O1 represents pretests

O2 represents posttests

X1 - AutoCAD 2-D Technique treatment

X2 - AutoCAD 3-D Technique treatment

Area of the Study

This study was conducted in all National Board for Technical Education (NBTE)

accredited polytechnics awarding National Diploma in Mechanical Engineering Technology

within the South-west Geo-political zone of Nigeria. The States in the zone include; Oyo,

Ogun, Osun, Ondo, Ekiti and Lagos states. The States are commercial location in the country.

59

73

Hence, there is a wide spread distribution of industries which needs the services of well-

trained mechanical engineering technicians. Also, the zone has many polytechnics offering

mechanical engineering technology whose students were used as subjects for the study.

Besides, the polytechnics have necessary facilities such as computer laboratory required to

conduct this study.

Population

The population for this study comprised all 350 ND I Mechanical Engineering

Technology students in all the seven Polytechnics offering Mechanical Engineering

Technology in South-west geo-political zone of Nigeria. The data were obtained from the

2007/2008 session of students register in the Head of Department’s (HOD’s) office in each of

the polytechnic. There are seven polytechnic offering Mechanical Engineering Technology in

south-western zone of Nigeria as at 2007/2008 session, namely; Federal Polytechnic, Ado

Ekiti, Ekiti State, Federal Polytechnic, Ilaro, Ogun State. Yaba College of Technology, Yaba,

Lagos State, The polytechnic, Ibadan, Oyo State, Rufus Giwa, Polytechnic, Owo, Ondo State,

Osun State College of Technology Esa Oke, Osun State, Lagos State Polytechnic, Ikeja,

Lagos State. See Appendix D for students’ distribution according to institutions.

Sample and Sampling Technique

The sample size for this study was 227 ND I mechanical engineering technology

students which comprised 206 Male and 21 Female students. Sampling for the study was

undertaken in two stages. In the first stage of the sampling, Non-proportionate stratified

random sampling technique was used to select two Federal Polytechnics and two State

Polytechnics from the list of Polytechnics offering mechanical engineering technology in the

South-western Geo-political zone of Nigeria. Thereafter, random sampling technique was

used to randomly assign two intact classes of ND 1 mechanical engineering technology

students from the two Federal polytechnics sampled to two treatments of AutoCAD, (i.e. one

intact class assigned to AutoCAD 2-D technique and the other assigned to AutoCAD 3-D

technique). Other intact classes of ND1 Mechanical engineering technology students in the

two State polytechnics sampled were also randomly assigned to two treatment of AutoCAD,

(i.e. one intact class assigned to AutoCAD 2-D technique and the other assigned to AutoCAD

3-D technique). In essence, two intact classes, (One from Federal polytechnic and One from

State Polytechnic) received AutoCAD 2-D techniques treatment. Also another two intact

classes, (One from Federal polytechnic and One from State Polytechnic) received AutoCAD

74

3-D technique treatment. In all, 108 ND I Mechanical Engineering Technology students

constituted treatment groups assigned to AutoCAD 2-D technique, while 119 ND I

Mechanical Engineering Technology students constituted another treatment group assigned to

AutoCAD 3-D technique.

Instruments for Data Collection

The instruments used in this study included: Purdue Visualization of Rotation Test

(PVRT), Engineering Graphics Achievement Test (EGAT), and Engineering Graphics Interest

Inventory. The PVRT developed by Bodner and Guay (1997) was adopted for the study. It

consisted of 20 multiple choice items designed to test how well students can visualize the

rotation of objects. In each question, The instruction on the PVRT tell the student to: (1) study

how the object in the top line of the question is rotated, (2) picture in your mind what the

object shown in the middle line of the question looks like when rotated in exactly the same

manner, and (3) select from among the five drawings (A, B, C, D, or E) given in the bottom

line of the question the one that looks like the object rotated in the correct position. To restrict

analytical processing, a time limit of 10 minutes for the 20-item version of this test was

strictly enforced. The EGAT which was used to test the achievement of students in

engineering graphics was developed by the researcher and it contained 45 multiple choice

items. The Engineering Graphics interest inventory which was used to test the students’

interest in engineering graphics was also developed by the researcher. The items of the

interest inventory were based on five point Likert scale type of Strongly Agreed (SA), Agreed

(A), Undecided (UD), Disagree (D) and strongly Disagree (SD). The AutoCAD 2-D, and 3-D

Lesson Plans which was used to teach the treatment groups were developed by the researcher.

Validation of the Instruments

The Purdue Visualization of Rotation Test (PVRT) had been validated by the test

developer (Bordner and Guay, 1997). According to the test developer, PVRT was subjected to

construct validity. To ensure content validity of the Engineering Graphics Achievement Test

(EGAT), a test blue print (Table of Specification) was built for the test given due

consideration to the emphasis placed on each objective and major topics in the engineering

graphics syllabus for ND I. Based on the table of specification, a total of eighty multiple

choice items were drawn for the EGAT. After which the PVRT, EGAT, Engineering Graphics

Interest Inventory, the AutoCAD 2-D and 3-D lesson plan and the Training plans for the

engineering graphics lecturers and students were subjected to face validation by five experts

which included; two Engineering Graphics lecturers in the polytechnics, Ibadan, a lecturer in

75

the Department of Architecture in the polytechnics, Ibadan and two measurement experts

from Faculty of Education, University of Nigeria Nsukka. In the face validation exercise, each

of the validators was served with a copy of each of the instrument for validation. Based on

the experts’ corrections and suggestions, preliminary screening and revision of the

instruments were made by the researcher.

A trial test was conducted on the EGAT for the purpose of determining the

psychometric indices of the test. In the trial test, the EGAT was administered on equivalent

sample of ND1 Mechanical engineering technology students in Kaduna Polytechnics, Kaduna.

The answer sheet were marked and used for computing the difficulty index, discrimination

index and distractor index of the test items. A total of 45 items of the EGAT had good

difficulty, discrimination and distractor indices as shown in Appendix ‘F’

In addition to face validation, the engineering graphics Interest Inventory was also

subjected to construct validation. The interest inventory was administered on equivalent

sample of ND1 Mechanical engineering technology students in Kaduna Polytechnics, Kaduna.

Factor analysis technique was used to select items that attain the factor-loading standard of

0.35 for the interest inventory. Also, items that failed to attain the factor loading standard or

loaded on more than one factor were dropped. This is because such items are said to be

factorially impure (Abonyi, 2005). Out of 40 items, a total of 28 items were finally selected.

See Appendix ‘G’ for result of the construct validation

Reliability of the instruments

The reliability for the Purdue Visualization of Rotations Test (PVRT) was reported by

Bodner and Guay (1997) using Kuder Richardson 20 Internal consistency test values of .80,

.78 and .80 for samples of 757, 850, 1273, respectively and Split Half Reliabilities were

reported of .83, .80, .84, .85, .82 and .78 for samples of 757, 850, 127, 1273, 1648 and 158

respectively. However, to account for varied cultural and social context a trial test was carried

out on the PVRT for determining its reliability coefficient. The PVRT was administered on

equivalent sample of ND1 Mechanical engineering technology students in Kwara State

Polytechnics. Split Half reliability was computed to be .82 for sample of 39 (Appendix ‘H’).

The trial test for determining the coefficient of stability of the Engineering Graphics

Achievement test (EGAT) was carried out using test re-test reliability technique. The

instrument was administered on equivalent sample of ND1 Mechanical engineering

technology students in Kwara State Polytechnics. The objectives answer sheets were marked

by the researcher and score kept. After two weeks, the EGAT was re-administered to the same

sample at Kwara State Polytechnics. The objectives answer sheets were also marked by the

76

researcher and the scores obtained in the first and second administration of the tests were

correlated. The reliability coefficient of the EGAT was found to be .80 using Pearson Product

Moment Correlation coefficient (Appendix ‘H’) Cronbach Alpha was used to determine the

internal consistency of the Engineering Graphics Interest Inventory items. The interest

inventory was administered on equivalent sample of ND1 Mechanical engineering technology

students in Kwara state polytechnics. The reliability coefficient computed for the Engineering

Graphics Interest inventory was found to be 0.91(Appendix ‘H’)

Control of Extraneous Variables

Experimental Bias

-To reduce experimental bias, the regular engineering graphics teachers in the

participating polytechnics taught their own students. Hence, the researcher was not

directly involved in administering the research instruments and the treatments

Lesson Plan Development

To control invalidity that could be caused by teacher variability in the development of

the lesson plans and to ensure uniform standard in the conduct of the research, the researcher

personally prepared the teaching instruments (the lesson plans) and organized training for

participating teachers. Two types of Lesson plan were developed by the researcher, namely:

AutoCAD 2-D lesson plan and AutoCAD 3-D lesson plan. The AutoCAD 2-D lesson plan

incorporated AutoCAD 2-D technique while AutoCAD 3-D lesson plan incorporated

AutoCAD 3-D technique

Training of Teachers for the treatment groups

A two weeks intensive training programme was organized for the engineering graphics

lecturers in all the schools sampled for the study. The lecturers that taught the treatment group

assigned to AutoCAD 2-D technique were given training and detailed explanations on the use

of AutoCAD 2-D technique, the use of AutoCAD 2-D lesson plan and the other research

procedures and expectations, while the lecturers that taught the treatment group assigned to

AutoCAD 3-D technique were given training and detailed explanations on the use of

AutoCAD 3-D technique, the use of AutoCAD 3-D lesson plan and the other research

procedures and expectations. In each of the cases, the researcher gave demonstration lessons

and requested the lecturers and their assistants to ask questions. Their questions were

answered. In order to ensure that the lecturers adhered to instructional principles and

procedures required in the use of the AutoCAD techniques and lesson plan, the lecturers were

asked to give demonstration lessons using the lesson plan developed by the researcher while

the researcher and some lecturers did assessment. The exercise was repeated until lecturers

77

were adjudged as capable of using the AutoCAD technique and the lesson plan appropriately.

The training plans for the teachers are shown in Appendix ‘E’

Other Experimental conditions controlled

The students in the treatment groups were not informed that they were being involved

in any research process. The same lesson contents were taught to all the treatment groups.

Experimental Procedure

The experiment commenced with the administration of pretest to all the treatment

groups. Engineering graphics lecturers and their assistants administered the pretest to the

treatment groups in their respective schools. In the pretest, the Engineering graphics

Achievement Test, the Purdue Visualization of Rotations Test and the Interest Inventory were

administered on the treatment groups. The exercise provided baseline data on each of the three

dependent variables (Achievement, Spatial Ability and Interest of each of the treatment group)

before the treatment.

After the pretest, a four weeks intensive training of AutoCAD techniques was given to

all the treatment groups by the Engineering graphics Lecturers in their respective schools. The

training for the treatment group assigned to AutoCAD 2-D techniques involved introduction

of the students to AutoCAD package and the use of AutoCAD 2-D techniques in AutoCAD

environment. While the training for treatment group assigned to AutoCAD 3-D techniques

involved introduction of the students to AutoCAD package and the use of AutoCAD 3-D

techniques in AutoCAD environment. See Appendix ‘E’ for the training plan for the students.

The training was immediately followed by the treatment.

During the treatment, the treatment group assigned to AutoCAD 2-D technique

treatment was taught with AutoCAD 2-D lesson plan. Engineering graphics lecturers in each

of the two participating schools used the AutoCAD 2-D lesson plans to teach their students.

Each of the classrooms used for the treatment was organized in such a away that there was

one computer for each student, a printer in a network and a projector for the lecturer. The

AutoCAD 2-D lesson plans incorporated AutoCAD 2-D techniques. The use of AutoCAD 2-

D techniques emphasized students’ active participation in the classroom instruction. Active

involvement was achieved through students’ interaction with AutoCAD command. The

lecturers placed learning in the hands of the students by making the students specify

dimensions in AutoCAD environment using absolute coordinate (X,Y) e.g., (1,3), relative

78

coordinate @(X,Y) e.g. @(2,5) polar coordinate @ (distance<angle) e.g @(50<90),

repeatedly to construct two-dimensional objects following AutoCAD command to interact

with the AutoCAD under the guidance of the lecturers. In addition, the students made use of

isometric grid in 2-D space for construction of three-dimensional objects. Furthermore, the

students constructed front view of a three-dimensional object in a tiled viewport using

AutoCAD 2-D techniques to specify dimensions and converted the front view in two-

dimension to three- dimensional objects, by responding to extrude command of AutoCAD

repeatedly, convert the object to virtual object and view the object as a solid object. Also, the

students constructed orthographic projection, section views and Auxiliary views of three-

dimensional objects through conversion of the three-dimensional objects to two-dimensional

objects by responding to soldraw and solview command of AutoCAD repeatedly under the

lecturer’s guidance. In all, the treatment group assigned to AutoCAD 2-D technique was

taught 14 lessons with the AutoCAD 2-D lesson plans. Each lesson lasted for 2 hours and the

treatment lasted for 7 weeks.

The treatment group assigned to AutoCAD 3-D techniques was taught with AutoCAD

3-D lesson plan. Engineering graphics lecturers in each of the two participating schools used

the AutoCAD 3-D lesson plans to teach their students. Each of the classrooms used for the

treatment was organized in such a away that there was one computer for each student, a

printer in a network and a projector for the lecturer. The AutoCAD 3-D lesson plans

incorporated AutoCAD 3-D techniques. During the treatment, the use of AutoCAD 3-D

techniques emphasized students’ active participation in the classroom instruction. Active

involvement was achieved through students’ interaction with AutoCAD command. The

lecturers placed learning in the hands of the students by making the students specify

dimensions using absolute coordinate in three-dimension (X,Y,Z) e.g., (1,3,4), relative

coordinate system in three-Dimension @(X,Y,Z) e.g. @(2,5,6) Spherical Coordinate system

@(distance<angle,<angle) e.g @50<60<30, repeatedly to construct two-dimensional objects

following AutoCAD command to interact with the AutoCAD under the guidance of the

lecturers. In addition, the students made use of absolute, relative and spherical coordinate

techniques in 3-Dimesional space for construction of three-dimensional objects. Also, the

students constructed orthographic projection, section views and Auxiliary views of three-

dimensional objects through conversion of the three-dimensional objects to its two-

dimensional format by responding to soldraw and solview command of AutoCAD repeatedly

under the lecturer’s guidance. Furthermore, the students constructed front view of a three-

dimensional object in a tiled viewport using AutoCAD 3-D techniques to specify dimensions

and converted the front view in two-dimension to three-dimensional objects, by responding to

79

extrude command of AutoCAD, rendered the object and view the object as a virtual object.

After which the students interacted repeatedly with the virtual objects in three-dimensional

space through use of animation of 3-D orbit command, 3-D continuous orbit command and

rotation of view point to the objects The interactions with the use of 3-D orbit command, and

3-D continuous orbit command involved panning, twisting, rotating, and rolling of the virtual

objects providing multi-point viewing relative to X,Y,Z coordinate system while interactions

with the use view point rotation involved changing viewers’ angle to object in 3-D space

without changing the object’s coordinate system. For instance, a rotation of 300 degree

position from the X-axis IN the XY plane and a 35 degree angle from the XY plane is shown

below:

The lecturer asked the students to use the 3-D coordinate (X,Y,Z) to rotate their View point to

the model as follows: use vpoint command to rotate their view point for angle of 270 degree

IN XY plane from X axis and 90 degree from the XY plane to view the TOP view of the

object in 2-D, use vpoint command to rotate their viewpoint for angle of 270 degree IN XY

plane from X axis and 0 degree from the XY plane to view the front view of the object in 2-D,

use vpoint command to rotate their viewpoint for angle of 0 degree IN XY plane from X axis

and 0 degree from the XY plane to view the Right Side View of the model in 2-D and use the

vpoint command to rotate their viewpoint for angle of 300 degree IN XY plane from X axis

and 35 degree from the XY plane to regenerate the TOP view, FRONT view and Right Side

View in 2-D to 3-D object. The use of 3-D orbit involved use of 3-D orbit command to rotate

object in three-Dimensional space to view the object as it rotates relative to the 3-D coordinate

orientation. i.e. X, Y, and Z. In all, the treatment group assigned to AutoCAD 3-D technique

was also taught 14 lessons with the AutoCAD 3-D lesson plans. Each lesson lasted for 2 hours

and the treatment also lasted for 7 weeks.

The posttest was administered to all the treatment groups immediately after the

completion of the treatments. Engineering graphics lecturers and their assistants administered

the posttest to the treatment groups in their respective schools. In the posttest, the

Engineering Graphics Achievement Test, the Purdue Visualization of Rotations Test and the

80

Interest Inventory were administered on the treatment groups. The exercise provided post

treatment data for each of the three dependent variables (Achievement, Spatial Ability and

Interest of each of the treatment group) after the treatment.

Method of Data Collection

Engineering graphics lecturers and their assistants administered the pretest to the

treatment groups in their respective schools. In the pretest, the Engineering Graphics

Achievement Test (EGAT), the Purdue Visualization of Rotations Test (PVRT) and the

Engineering Graphics Interest Inventory were administered on the treatment groups. Objective

Answer sheet were provided for the students to fill in the correct answers for the Engineering

graphics achievement test and the Purdue Visualization of Rotation Test. The students

checked (√) to indicate the degree to which they agreed or disagreed with the statements in the

Engineering graphics interest inventory. The researcher marked the answer sheets of the

EGAT and the PVRT to obtain the students’ scores on cognitive achievement and spatial

ability in engineering graphics before the treatment while the interest inventory was scored by

the researcher to determine each of the student’s interest before the treatment. The exercise

provided baseline data on each of the three dependent variables (Achievement, Spatial Ability

and Interest of each of the treatment group) before the treatment.

During the posttest, engineering graphics lecturers and their assistants administered the

posttest to the treatment groups in their respective schools. In the posttest, the Engineering

Graphics Achievement Test, the Purdue Visualization of Rotations Test and the Engineering

Graphics Interest Inventory were administered on the treatment groups. Objective Answer

sheet were provided for the students to fill in the correct answers for the Engineering graphics

achievement test and the Purdue Visualization of Rotation Test. The students checked (√) to

indicate the degree to which they agreed or disagreed with the statements in the Engineering

graphics interest inventory. The researcher marked the answer sheets of the EGAT and the

PVRT to obtain the students’ scores on cognitive achievement and spatial ability in

engineering graphics after the treatment while the Engineering Graphics interest inventory

was scored by the researcher to determine each of the student’s interest after the treatment.

The exercise provided post treatment data for each of the three dependent variables

(Achievement, Spatial Ability and Interest of each of the treatment group) after the treatment.

81

Methods of Data Analysis

The data collected from the administration of pretest and posttest, were analyzed using

mean to answer the research questions. The pretest-posttest mean gain of each of the treatment

group was computed to determine the effects of the two techniques of AutoCAD (2-D and 3-

D) and effect of the Gender (Male and female) on spatial ability, interest and achievement in

engineering graphics

Meanwhile, Hypotheses formulated for the study were tested at .05 level of

significance using Analysis of Covariance (ANCOVA). This is because ANCOVA is a

statistical technique which removes the initial differences between groups, so that the selected

or pre-tested groups can be correctly considered as equated or equivalent by removing score

difference in the pretest performance across groups and reducing the between-group source

variation (Ali, 1996). According to Ary, Jacob and Razavieh (2000) ANCOVA is a method

for analysing differences between experimental groups on the dependent variable after taking

into account any initial differences between the groups on pretest measures or on any other

measures of relevant independent variables. Such a measure used for control is called a

covariate. Since students in their intact classes participated in this experiment, ANCOVA was

considered appropriate for analyzing the differences between the main effects of the

treatments on the dependent variables

82

CHAPTER IV

PRESENTATION AND ANALYSIS OF DATA

This Chapter presents the results and discussions of the data analyses for the study.

The presentations were organized according to the research questions and null hypotheses that

guided the study

Research Question 1

What is the effect of AutoCAD techniques (2-D and 3-D) on students’ achievement in


Table 1

Mean of Pretest and Posttest Scores of Treatment Groups taught Engineering Graphics with AutoCAD techniques (2-D and 3-D) in the Engineering Graphics Achievement Test AutoCAD Techniques N Pretest Posttest

Mean Gain X X AutoCAD 2-D Technique 108 3.50 32.50 29.00 AutoCAD 3-D Technique 119 3.94 40.84 36.90

The data presented in Table 1 show that the treatment group taught engineering

graphics with AutoCAD 2-D technique had a mean score of 3.50 in the pretest and a mean

score of 32.50 in the posttest making a pretest, posttest mean gain in the treatment group

taught with AutoCAD 2-D technique to be 29.00. The treatment group taught engineering

graphics with AutoCAD 3-D technique had a mean score of 3.94 in the pretest and a posttest

mean of 40.84 with a pretest, posttest mean gain of 36.90. With these results, both AutoCAD 2-

D technique and AutoCAD 3-D technique are effective in improving students’ achievement in

engineering graphics but the effect of AutoCAD 3-D technique on students’ achievement in

engineering graphics is higher than the effect of AutoCAD 2-D technique.

Research Question 2

What is the effect of using AutoCAD (2-D and 3-D) techniques in teaching

Engineering graphics on students’ spatial ability measured by Purdue Visualization of

Rotations Test (PVRT)?

69

83

Table 2

Mean of Pretest and Posttest Scores of Treatment Groups taught Engineering Graphics with AutoCAD techniques (2-D and 3-D) in the Purdue Visualization of Rotations Test (PVRT) AutoCAD Techniques N Pretest Posttest


Table 2 shows that the treatment group taught engineering graphics with AutoCAD 2-

D technique had a mean score of 1.87 in the pretest and a mean score of 6.81 in the posttest

making a pretest, posttest mean gain in the treatment group taught with AutoCAD 2-D

technique to be 4.94. The treatment group taught engineering graphics with AutoCAD 3-D

technique had a mean score of 1.90 in the pretest and a posttest mean of 14.68 with a pretest,

posttest mean gain of 12.78. With these results, both AutoCAD 2-D technique and AutoCAD 3-

D technique are effective in improving students’ spatial ability in engineering graphics but the

effect of AutoCAD 3-D technique on students’ spatial ability in engineering graphics is higher

than the effect of AutoCAD 2-D technique.

Research Question 3

What is the effect of using AutoCAD (2-D and 3-D) technique on students’ interest in

studying Engineering graphics?

Table 3

Mean of Pretest and Posttest Scores of Treatment Groups taught Engineering Graphics with AutoCAD techniques (2-D and 3-D) in the Engineering Graphics Interest Inventory AutoCAD Techniques N Pretest Posttest


The data presented in Table 3 shows that the treatment group taught engineering

graphics with AutoCAD 2-D technique had a mean score of 87.11 in the pretest and a mean

score of 134.14 in the posttest making a pretest, posttest mean gain in the treatment group

taught with AutoCAD 2-D technique to be 47.03. The treatment group taught engineering


mean of 135.07 with a pretest, posttest mean gain of 47.49. With these results, both AutoCAD 2-

D technique and AutoCAD 3-D technique are effective in improving students’ interest in

84

engineering graphics but the effect of AutoCAD 3-D technique on students’ interest in

engineering graphics is higher than the effect of AutoCAD 2-D techniques.

Research Question 4

What is the effect of Gender on the spatial ability test scores of students (male and

female) when taught engineering graphics with AutoCAD techniques?

Table 4

Mean of Pretest and Posttest of Male and Female Students Taught Engineering Graphics with AutoCAD techniques (2-D and 3-D) in the Purdue Visualization of Rotations Test (PVRT)

Gender

AutoCAD Techniques AutoCAD 2-D Technique AutoCAD 3-D Technique

n

Pretest

Posttest

Mean Gain

X

n

Pretest

Posttest

Mean Gain

X Male 98 1.93 7.08 5.15 108 1.99 14.93 12.94

Female 10 1.20 4.20 3.00 11 1.09 12.18 11.09

Table 4 shows that male students taught engineering graphics with AutoCAD 2-D

technique had a mean score of 1.93 in the pretest and a mean score of 7.08 in the posttest

making a pretest, posttest mean gain in the male students taught with AutoCAD 2-D technique

to be 5.15. Meanwhile, female students taught engineering graphics with AutoCAD 2-D

technique had a mean score of 1.20 in the pretest and a posttest mean of 4.20 with a pretest,

posttest mean gain of 3.00. Also, male students taught with AutoCAD 3-D technique had a

mean score of 1.99 in the pretest and a mean score of 14.93 in the posttest, making a pretest,

posttest mean gain in the male students taught with AutoCAD 3-D technique to be 12.94.

Meanwhile, female students taught engineering graphics with AutoCAD 3-D technique had a

mean score of 1.09 in the pretest and a posttest mean of 12.18 with a pretest, posttest mean

gain of 11.09. With these results male students taught engineering graphics with AutoCAD

techniques had higher mean scores than female students in the Purdue Visualization of

Rotations Test (PVRT). Thus, there is an effect attributable to gender on spatial ability of

students taught engineering graphics with AutoCAD techniques.

85

Research Question 5

What is the effect of Gender on the achievement of students (male and female) when

taught engineering graphics with AutoCAD techniques?

Table 5 Mean of Pretest and Posttest of Male and Female Students Taught Engineering Graphics with AutoCAD techniques (2-D and 3-D) in the Engineering Graphics Achievement Test

Gender


n

Pretest

Posttest

Mean Gain

X

n

Pretest

Posttest

Mean Gain

X Male 98 3.54 33.00 29.46 108 3.96 41.23 37.27

Female 10 3.10 27.60 24.50 11 3.81 37.00 33.19

The data presented in Table 5 shows that male students taught engineering graphics

with AutoCAD 2-D technique had a mean score of 3.54 in the pretest and a mean score of

33.00 in the posttest making a pretest, posttest mean gain in the male students taught with

AutoCAD 2-D technique to be 29.46. Meanwhile, female students taught engineering


mean of 27.60 with a pretest, posttest mean gain of 24.50 Also, male students taught with

AutoCAD 3-D technique had a mean score of 3.96 in the pretest and a mean score of 41.23 in

the posttest making a pretest, posttest mean gain in the male students taught with AutoCAD 3-

D technique to be 37.27. Meanwhile, female students taught engineering graphics with

AutoCAD 3-D technique had a mean score of 3.81 in the pretest and a posttest mean of 37.00

with a pretest, posttest mean gain of 33.19. With these results male students taught

engineering graphics with AutoCAD techniques had higher mean scores than female students

in the Engineering Graphics Achievement Test. Thus, there is an effect attributable to gender

on the achievement of students taught engineering graphics with AutoCAD techniques.

Research Question 6

What is the effect of Gender on the interest of students (male and female) when taught

engineering graphics with AutoCAD techniques?

86

Table 6

Mean of Pretest and Posttest of Male and Female Students Taught Engineering Graphics with AutoCAD techniques (2-D and 3-D) in the Engineering Graphics Interest inventory

Gender


n

Pretest

Posttest

Mean Gain

X

n

Pretest

Posttest

Mean Gain

X Male 98 87.18 134.29 47.11 108 87.73 135.23 47.50

Female 10 86.40 133.50 47.10 11 86.18 133.45 47.27

The data presented in Table 6 show that male students taught engineering graphics

with AutoCAD 2-D technique had a mean score of 87.18 in the pretest and a mean score of

134.29 in the posttest making a pretest, posttest mean gain in the male students taught with

AutoCAD 2-D technique to be 47.11. Meanwhile, female students taught engineering


mean of 133.50 with a pretest, posttest mean gain of 47.10 Also, male students taught with

AutoCAD 3-D technique had a mean score of 87.73 in the pretest and a mean score of 135.23

in the posttest making a pretest, posttest mean gain in the male students taught with AutoCAD

3-D technique to be 47.50. Meanwhile, female students taught engineering graphics with

AutoCAD 3-D technique had a mean score of 86.18 in the pretest and a posttest mean of

133.45 with a pretest, posttest mean gain of 47.27. With these results male students taught

engineering graphics with AutoCAD techniques had higher mean scores than female students

in the Engineering Graphics Interest Inventory. Thus, there is an effect attributable to gender

on the interest of students taught engineering graphics with AutoCAD techniques.

Hypotheses


(AutoCAD 2-D and 3-D techniques) on students’ achievement in Engineering

Graphics


female) on students’ achievement in Engineering Graphics



Graphics Achievement Test

87

Table 7 Summary of Analysis of Covariance (ANCOVA) for Test of Significance of Main Effect of Treatments and Gender and Interaction Effect of Treatments given to Students Taught with AutoCAD and their Gender with Respect to their Mean Scores on Engineering Graphics Achievement Test

Source of Variation Sum of Squares

DF Mean Square F Sig of F

Covariates 20.539 1 20.539 3.134 .078 Pre-test 20.539 1 20.539 3.134 .078

Main Effects 1781.060 2 890.530 135.868 .000 Treatment 1419.413 1 1419.413 216.559* .000

Gender 428.346 1 428.346 65.352* .000 2-way Interactions 5.817 1 5.817 .887 .347 Treatment*Gender 5.817 1 5.817 .887 .347 Explained 4402.221 4 1100.555 167.911 .000 Residual 1455.074 222 6.554 TOTAL 5857.295 226 25.917

*Significant at sig of F< .05

The data presented in Table 7 shows F-calculated values for three effects: treatment,

gender and interaction effect of treatments and gender on students’ achievement in

engineering graphics. The F-calculated value for treatment is 216.559 with a significance of F

at .000 which is less than .05. The null-hypothesis is therefore rejected at .05 level of

significance. With this result, there is a significant difference between the effect of treatments

(AutoCAD 2-D and 3-D techniques) on students’ achievement in engineering graphics. The F-

calculated value for gender is 65.352 with a significance of F at .000 which is less than .05.

This means that there is significant difference between the effect of Gender on students’

achievement in engineering graphics. Therefore, the null hypothesis of no significant

difference between the effect of gender (male and female) on students’ achievement in

engineering graphics is rejected at .05 level of significance. The interaction of treatments and

gender has F-calculated value of .887 with significance of F of .347. Since .347 is higher than

.05, the null hypothesis for interaction effect of treatment and gender is accepted. Hence, there

is no significant interaction effect of treatments given to students taught with AutoCAD and

their gender with respect to their mean scores on Engineering Graphics Achievement Test


(AutoCAD 2-D and 3-D techniques) on students’ spatial ability in Engineering

Graphics


female) on students’ spatial ability in Engineering Graphics

88


with AutoCAD and their gender with respect to their mean scores on the Purdue


Table 8 Summary of Analysis of Covariance (ANCOVA) for Test of Significance of Main Effect of Treatment and Gender and Interaction Effect of Treatments Given to Students Taught With AutoCAD and their Gender with Respect to their Mean Scores on Purdue Visualization of Rotations Test



Covariates 51.396 1 51.396 11.790 .001 Pre-test 51.396 1 51.396 11.790 .001

Main Effects 1340.067 2 670.034 153.707 .000 Treatment 1187.999 1 1187.999 272.529* .000

Gender 184.015 1 184.015 42.213* .000 2-way Interactions .014 1 .014 .003 .954 Treatment*Gender .014 1 .014 .003 .954 Explained 3705.403 4 926.351 212.507 .000 Residual 967.733 222 4.359 TOTAL 4673.137 226 20.678


Table 8 shows F-calculated values for three effects: treatment, gender and interaction

of treatment and gender on students’ spatial ability in engineering graphics. The F-calculated

value for treatment is 272.529 with a significance of F at .000 which is less than .05. The null-

hypothesis of no significant difference between the effect of treatments (AutoCAD 2-D and 3-

D techniques) on students’ spatial ability in engineering graphics is therefore rejected at .05

level of significance. The F-calculated value for gender stood at 42.213 with a significance of

F at .000 which is less than .05. The null hypothesis is therefore rejected at .05 level of

significance. This result means that there is statistically significant effect of gender (male and

female) on students’ spatial ability in engineering graphics. The interaction effect of treatment

and gender has F-calculated value of .003 with significance of F of .954 which is higher than

.05. Hence, the null hypothesis of no significant interaction effect of treatments given to

students taught with AutoCAD and their gender with respect to their mean scores on the

Purdue Visualization of Rotations Test is accepted.


(AutoCAD 2-D and 3-D techniques) on students’ interest in Engineering Graphics


female) on students’ interest in Engineering Graphics

89



Graphics Interest Inventory.

Table 9 Summary of Analysis of Covariance (ANCOVA) for Test of Significance of Main Effect of Treatments and Gender and Interaction Effect of Treatments Given to Students Taught with AutoCAD and their Gender with Respect to their Mean Scores on Engineering Graphics Interest Inventory



Covariates 6.358 1 6.358 .856 .356 Pre-test 6.358 1 6.358 .856 .356

Main Effects 31.694 2 15.847 2.135 .121 Treatment 4.516 1 4.516 .608 .436

Gender 28.007 1 28.007 3.773 .053 2-way Interactions 5.300 1 5.300 .714 .399 Treatment*Gender 5.300 1 5.300 .714 .399 Explained 91.171 4 22.793 3.070 .017 Residual 1648.000 222 7.423 TOTAL 1739.172 226 7.695


The data presented in Table 9 shows F-calculated for three effects: treatment, gender

and interaction of treatment and gender on students’ interest in engineering graphics. The F-

calculated value for treatment is .608 with a significance of F at .436 which is greater than .05.

Hence, the null hypothesis of no significant difference between the effect of treatments

(AutoCAD 2-D and 3-D techniques) on students’ interest in engineering graphics is upheld at

.05 level of significance. The F-calculated for gender stood at 3.773 with a significance of F at

.053 which is greater than .05. The null-hypothesis is therefore accepted at .05 level of

significance. With this result there is no significant difference between the effect of gender

(male and female) on students’ interest in engineering graphics. The interaction effect of

treatment and gender has F-calculated value of .714 with significance of F of .399 which is

greater than .05. This result means that there is no significant interaction effect of treatments

given to students taught with AutoCAD and their gender with respect to their mean scores on

Engineering Graphics Interest Inventory

90

Findings of the Study

The following findings emerged from the study based on the data collected and

analyzed and hypothesis tested

1. AutoCAD 2-D and AutoCAD 3-D techniques are effective in improving students’

achievement in engineering graphics but the effect of AutoCAD 3-D technique on

students’ achievement in engineering graphics is higher than the effect of AutoCAD 2-

D technique.

2. AutoCAD 2-D technique and AutoCAD 3-D technique are effective in improving

students’ spatial visualization in engineering graphics but the effect of AutoCAD 3-D

technique on students’ spatial ability in engineering graphics is higher than the effect

of AutoCAD 2-D technique.

3. AutoCAD 2-D technique and AutoCAD 3-D technique are effective in stimulating

students’ interest in engineering graphics but the effect of AutoCAD 3-D technique on

students’ interest in engineering graphics is higher than the effect of AutoCAD 2-D

techniques.

4. It was found out that gender has effect on students’ spatial ability in engineering

graphics in favour of male students

5. It was found out that gender has effect on students’ achievement in engineering

graphics in favour of male students

6. It was found out that gender has effect on students’ interest in engineering graphics in

favour of male students

7. There was a significant mean difference between the effect of treatments (AutoCAD

2-D and 3-D techniques) on students’ achievement in engineering graphics.

8. There was a significant mean difference between the effect of Gender on students’

achievement in engineering graphics.

9. There was no significant interaction effect of treatments given to students taught with

AutoCAD and their gender with respect to their mean scores on Engineering Graphics

Achievement Test

10. There was a significant mean difference between the effect of treatments (AutoCAD

2-D and 3-D techniques) on students’ spatial ability in engineering graphics

11. There was a significant mean difference between the effect of gender (male and

female) on students’ spatial ability in engineering graphics


AutoCAD and their gender with respect to their mean scores on the Purdue


91

13. There was no significant mean difference between the effect of treatments (AutoCAD

2-D and 3-D techniques) on students’ interest in engineering graphics

14. There was no significant mean difference between the effect of gender (male and

female) on students’ interest in engineering graphics

15. There was no interaction effect of treatments given to students taught with AutoCAD

and their gender with respect to their mean scores on Engineering Graphics Interest

Inventory

Discussion

The data presented in Table 1 provided answer to research question one, finding

revealed that AutoCAD 2-D technique and AutoCAD 3-D technique are effective in

improving students achievement in engineering graphics but the effect of AutoCAD 3-D

technique on students’ achievement in engineering graphics is higher than the effect of

AutoCAD 2-D technique. At the same time, Analysis of covariance was used to test the first

hypothesis, Table 7, at the calculated F-value (216.559), Significance of F (.000) and

confidence level of .05 there was a statistically significant difference between the effect of

treatments (AutoCAD 2-D and 3-D techniques) on students achievement in engineering

graphics confirming that the difference between the effect of AutoCAD 3-D and AutoCAD 2-

D was statistically significant. The implication of this finding is that AutoCAD 3-D technique

is more effective than AutoCAD 2-D technique in enhancing students’ achievement in

engineering graphics. This finding compared favourably with the finding of a research

conducted in United States by Thomas (1996) reported by Scribner and Anderson (2005).

Research by Thomas (1996) tested the benefits of three-dimensional CADD instruction over

instruction using two-dimensional CADD. Results showed the three-dimensional CADD

method of instruction was more effective than the two-dimensional CADD method. This

finding could be explained by the fact that the three-dimensional coordinate system provides

the three physical dimensions of space-height, width and length (Branof, 1998). Basham

(2007) noted that drawing in three-dimension have significant communication advantages by

representing form and space more realistically. In the view of Mohler (2006) 3-D technique

provides different perspective views to provide the user a sense of an objects’ orientation in

space. Thus, this result is attributed to the fact that three physical dimensions of space-height,

width and length favour a deeper understanding of the meaning of geometric construction in

the treatment groups assigned to AutoCAD 3-D technique.

92

In addition, Analysis of covariance was used to test the third hypothesis Table 7, at the

calculated F-value (.887), significance of F (.347) and confidence interval of 0.05 there was

no significant interaction effect of treatments given to students taught with AutoCAD and

their gender with respect to their mean scores on engineering graphics achievement test. This

result showed that the effectiveness of AutoCAD techniques on students’ achievement in

engineering graphics does not depend on the level of gender. Hence, there were no differential

effects of treatments over levels of gender (male and female), which implies that AutoCAD 3-

D technique is more effective than AutoCAD 2-D in improving students’ achievement in

engineering graphics regardless of Gender levels.

The data presented in Table 2 provided answer to research question two. Findings

revealed that AutoCAD 2-D technique and AutoCAD 3-D technique is effective in improving

students spatial ability in engineering graphics but the effect of AutoCAD 3-D technique on

students’ spatial ability in engineering graphics is higher than the effect of AutoCAD 2-D

technique. At the same time, Analysis of covariance was employed to test the fourth

hypothesis, Table 8, at the calculated F- value (272.529), significance of F (.000) and

confidence level of .05, there was a significant difference between the effect of treatments

(AutoCAD 2-D and 3-D techniques) on students’ spatial ability in engineering graphics which

confirmed that the difference between the effect of AutoCAD 3-D technique and AutoCAD 2-

D technique on students’ spatial ability was statistically significant. This implies that

AutoCAD 3-D technique is more effective than AutoCAD 2-D technique in improving

students’ spatial ability in engineering graphics. Spatial ability is multifaceted. Alias et al.,

(2002) pointed out that providing diverse activities is the key to enhancing overall spatial

visualization ability. In addition to drawing geometry with AutoCAD 3-D technique, the

participants assigned to 3-D technique were able to solve spatial tasks by interactions with

animation and virtual object through panning, twisting, rotating, and rolling of the virtual

objects providing multi-point viewing relative to x,y,z coordinate system and with the use of

view point rotation that involved changing viewers’ angle to object in 3-D space without

changing the object’s coordinate system, thus facilitating the visual perception and processing

of objects in the 3-D space. The use of x,y,z coordinate system and the high degree of

interaction with virtual objects and animation in the AutoCAD 3-D environment had benefited

the treatment groups assigned to AutoCAD 3-D technique since these features are absent in

the AutoCAD 2-D technique. Rafi, Samsudin and Said (2008) noted that 3-D technique

provides 3-D space learning environment that facilitates better understanding of spatial

properties and relationships of objects and space. They explained that 3-D environment allow

real time interactions by means of one or more control devices and involving one or more

93

sensorial perception. In the 3-D environment, learners could view objects from close up or

from a distance when examining specific and holistic feature of the artefacts thus concurring

with Smith’s (2001) study that suggested alternating between interaction and observation was

the best way to learn spatial visualization. Additionally, theories such as Piaget’s theory of

cognitive development supported this interaction. The theory placed emphasis on the fact that

spatial knowledge is developed as human being interacts with objects in their environment

(Nwachukwu, 1995).

In the same vein, Analysis of covariance was also used to test the sixth hypothesis,

Table 8. At the calculated F-value (.003), significance of F (.954) and confidence level of .05,

there was no significant interaction effect of treatments given to students taught with

AutoCAD and their gender with respect to their mean scores on the Purdue Visualization of

Rotations Test. With these results there were no differential effects of AutoCAD treatments

over all levels of gender. Thus, AutoCAD 3-D technique is more effective in improving

students’ spatial ability in engineering graphics regardless of levels of Gender.

The data presented in Table 3 provided answer to research question three. Finding

revealed that both AutoCAD 2-D and AutoCAD 3-D technique in improving students interest

in engineering graphic but the effect of AutoCAD 3-D technique on students’ interest in

engineering graphics is higher than the effect of AutoCAD 2-D techniques. This finding

indicates that AutoCAD 3-D technique is more effective in stimulating students’ interest in

engineering graphics than the 2-D technique. However, the Analysis of covariance of the

treatments effects on interest presented in Table 9 showed that there was no significant

difference between the effects of treatments (AutoCAD 2-D and 3-D techniques) on students’

interest in engineering graphics. Thus, the difference between the AutoCAD 3-D technique

and AutoCAD 2-D technique on students’ interest in engineering graphics was not found

significant. Furthermore, another salient finding from this study is that it was found out that

male students taught engineering graphics with AutoCAD techniques had higher mean scores

than female students in the Engineering Graphics Interest Inventory, revealing that there is an

effect attributable to gender on the interest of students taught engineering graphics with

AutoCAD techniques. However, analysis of covariance of test of significant difference

between the effect of gender on students’ interest in engineering graphics as presented in

Table 9 showed that there was no significant difference between the effect of gender (male

and female) on students’ interest in engineering graphics. This means that the observed

difference in the mean interest scores of male and female students was not statistically

significant. Interestingly, providing opportunities to interact with course material through the

use of computers and information technology tends to change the course from a competitive

94

endeavour to one that is more student-centred, and focused on the cognitive development and

construction of knowledge in the students (Brewer, 2003). Hence, one means of constructing

knowledge is to create meaning by doing. Creating support for knowledge construction within

the students is a critical component to the success of developing self-motivated, intellectually

stimulated learners (Osberg, et al., 1997). The obvious implication of the use of computer in

the classroom therefore, is to facilitate students’ interaction with the learning environment so

as to sustain students’ direct interest which increases the strength of ego-involvement of the

learners and which does not allow the learners to be distracted by trivial extraneous events in

the perceptual environment.

Analysis of covariance was used to test hypothesis nine, Table 9, at the calculated F-

value (.714), significance of F (.399) and confidence level of .05, the interaction effect of

treatment and gender was not found to be significant. This implies that the effectiveness of

AutoCAD techniques on students’ interest in engineering graphics does not depend of gender

level.

The data presented in Table 4 provided answer to research question four. Finding

revealed that male students taught engineering graphics with AutoCAD techniques had higher

mean scores than female students in the Purdue Visualization of Rotations Test (PVRT).

Thus, there is an effect attributable to gender on spatial ability of students taught engineering

graphics with AutoCAD techniques. At the same time, Analysis of covariance was employed

to test the fifth hypothesis, Table 8, at the calculated F- value (42.213), significance of F

(.000) and confidence level of .05 there was a significant difference between the effect of

gender (male and female) on students’ spatial ability in engineering graphics which confirmed

that the difference between the spatial ability test scores of male and female students in

engineering graphics was statistically significant favouring boys. This finding confirmed the

finding that there was an effect attributable to gender on spatial ability of students in

engineering graphics. This finding is similar to findings of several other studies that had been

conducted on gender effects on spatial ability of male and female students in engineering and

other fields. For instances, one of the important discoveries emerging from studies involving

psychometric testing of spatial ability was the revelation of gender differences favouring boys.

Generally, boys were consistently found to perform better than girls on spatial ability tests

suggesting that boys generally possess greater spatial skills than girls. Male advantages in

spatial ability have been established in studies by Nemeth and Hoffmann (2006), Burin,

Delgado and Prieto (2000), Medina, Gerson and Sorby (2000) and Branoff (1998), Voyer,

Voyer, and Bryden (1995), Linn and Petersen (1985), and Maccoby and Jacklin (1974), where

the trends of gender differences were found to be stable and consistent. Thus, in studies where

95

differences in spatial ability were evident males typically had stronger spatial skills than girls.

Male superiority in spatial ability than girls is supported by Baenninger and Newcombe

(1989) who noted that training does not eliminate differences between spatial ability of male

and female but rather improve their scores.

Furthermore, the data presented in Table 5 provided answer to research question five.

Findings revealed that male students taught engineering graphics with AutoCAD techniques

had higher mean scores than female students in the Engineering Graphics Achievement Test.

Thus, there is an effect attributable to gender on the achievement of students taught

engineering graphics with AutoCAD techniques. Analysis of covariance was used to test

hypothesis two, Table 7. At the calculated F-value (65.352), significance of F (.000) and

confidence level of .05, there was a significant difference between the effect of gender on

students’ achievement in engineering graphics. The plausible explanation for this finding is

that spatial ability has been identified as one of the most important skills related to

achievement in engineering and technical graphics because of its direct relationship to the

graphical communication associated with design (Koch, 2005). Thus, spatial ability has

correlation with achievement in engineering. According to Scribner and Anderson (2005) well

developed spatial skills have been proven to be critical to a technical person’s ability to

develop creative design solution to engineering problems. Even, in cases where non-spatial

strategies are required, spatial ability influences the degree to which a problem solver is able

to develop and evaluate strategies (Alias et al., 2002). This is because problem solving

commonly uses perceptual representations to partially encode the problem elements involved,

which is helpful in supporting inferences (Basham, 2007). Besides, in problem solving, a

mental model must first be created and regardless of the representation, the mental

construction is most important for problem solving (Jonassen, 2000). Additionally, Benbow

and Stanley (1980; 1983) attributed gender differences in achievement to girls’ innate

inferiority in spatial visualization. Therefore, The identified gender effect on spatial ability in

engineering graphics was responsible for the significant gender effect found on students’

achievement in engineering graphics. Thus, the superiority of male spatial ability had

responsible for their improved achievement in engineering graphics.

96

CHAPTER V

SUMMARY, CONCLUSIONS AND RECOMMENDATIONS

Re-statement of the Problem

Computer-Aided Design (CAD) is the use of a wide range of computer-based tools

that assist engineers, architects and other design professionals in their design activities. It is

the main engineering graphics tool and involves both software and sometimes special-purpose

hardware. Since the advent of 2-D CAD, there has been a wide acceptance of CAD packages

in education community as a learning tool for geometry construction and other graphics

designs in various disciplines due to its potential to engage students in the learning tasks,

improving students’ interest, achievement and visualization. The recent introduction of highly

sophisticated, low-cost CAD software capable of running on desktop computers has

accelerated this trend.

Current CAD packages today range from 2-D vector based drafting systems to 3-D

parametric software packages. The emergence of CAD packages such as AutoCAD which is

capable of both 2-D and 3-D coordinate techniques of graphics has had a major impact on

mapping, graphics design, and manufacturing, thereby reducing design effort, testing, and

prototype work. This has resulted in significantly reduced costs and improved productivity in

the industry. Therefore, many engineering industry would like to employ graduating

engineering students who are familiar with one or two CAD packages for graphics design

(Branoff, 2005). Irrespective, of the ample use of CAD packages in the industry for

engineering graphics, demonstration with drawing instruments on chalk board is

predominantly used to teach engineering graphics to the National Diploma students in the

polytechnics. Apart from the fact that demonstration method is teacher-centred; it does not

provide learning environment that facilitates better understanding of spatial properties and

relationship of objects and space. Another major limitation of the method is the problem of

presenting three-dimensional (3-D) spatial information in a two-dimensional format (2-D)

(Mackenzie and Jansen, 2005). Accordingly, many students taught graphics with the method

have difficulty in comprehending the graphics representation of three-dimensional objects

(Scribner and Anderson, 2005).

Moreover, the use of demonstration with drawing instruments on the chalkboard

apparently, results into neglect in the development of students’ spatial ability which invariably

leads to deprivation of students in everyday applications, such as translating 2-D objects to 3-

D objects, poor at estimating sizes and poor at visualizing things and relationships to one

another (Koch, 2006). Consequently, this situation leads to students’ poor academic

achievement due to inadequate learning environment for developing the spatial ability

83

97

essential in engineering graphics and sustain students’ interest in learning. Besides, students

taught using demonstration method with drawing instruments on the chalk board will

obviously lack engineering graphics design skills required for work in the industry due to

ample use of CAD packages. It becomes pertinent to teach engineering graphics of National

Diploma students with AutoCAD which is used in the industry due to its wide range of

application capabilities and techniques. AutoCAD has two techniques of drawing: Two-

dimensional (2-D) and Three-dimensional (3-D) techniques. When drawing with 3-D

techniques in AutoCAD environment user no longer deals with only x and y coordinates, but

also with the z-axis as well. Thus, drawing with 2-D techniques is different from drawing with

3-D technique. This difference perhaps, may produce different effects on students’

achievement, interest and spatial ability in learning engineering graphics. This situation

therefore prompted one to ask: what is the comparative effect of AutoCAD (2-D and 3-D

techniques) on National Diploma students’ spatial ability, interest and achievement in


Summary of Procedure Used

The study was a pretest, posttest, non-equivalent control group quasi-experiment

which involved groups of students in their intact classes assigned to treatment groups for

determining the effects of AutoCAD (2-D and 3-D techniques) as an independent variable and

gender (Male and Female) as a moderator variable on spatial ability, interest and achievement

of National Diploma students in engineering graphics.

Specific objectives of the study were to determine:

• Effect of AutoCAD techniques (2-D, and 3-D) on students’ achievement in


• Effect of using AutoCAD techniques (2-D, and 3-D) in teaching engineering graphics

on students’ spatial ability measured by Purdue Visualization of Rotations Test

(PVRT).

• Effect of AutoCAD techniques (2-D, and 3-D) use on students’ interest in studying


• Effect of Gender on the spatial ability test scores of students (male and female) taught

with AutoCAD techniques.

• Effect of Gender on the achievement of students (male and female) taught engineering

graphics with AutoCAD techniques.

• Effect of Gender on the interest of students (male and female) taught engineering

graphics with AutoCAD techniques.

98

To fulfill these objectives, six research questions were formulated. The population of

the study were all 350 ND I mechanical engineering technology students in the polytechnics

in the south-western geo-political zone of Nigeria. The sample size was 227 students from

which 108 ND I Mechanical Engineering Technology students which comprised 98 male and

10 female constituted treatment groups assigned to AutoCAD 2-D technique, and 119 ND I

Mechanical Engineering Technology students which comprised 108 male and 11 female

constituted another treatment groups assigned to AutoCAD 3-D technique. The instruments

used in this study included: Purdue Visualization of Rotation Test (PVRT), Engineering

Graphics Achievement Test (EGAT), and Engineering Graphics Interest Inventory.

The Purdue Visualization of Rotation Test (PVRT) had been validated by test

developer (Bordner and Guay, 1997). To ensure content validity of the Engineering Graphics

Achievement Test (EGAT), a test blue print (Table of Specification) was built for the test

given due consideration to the emphasis placed on each objective and major topics in the

engineering graphics syllabus. Based on the Table of specification, a total of eighty multiple

choice items were drawn for the EGAT. After which the PVRT, EGAT, Engineering Graphics

Interest Inventory, the AutoCAD 2-D and 3-D lesson plan and the Training plans for the

engineering graphics lecturers and students were subjected to face validation by five Experts.

The EGAT was trial tested for the purpose of determining the psychometric indices of the test.

A total of 45 items of the EGAT had good difficulty, discrimination and distractor indices. In

addition to face validation, the engineering graphics Interest Inventory was also subjected to

construct validation using factor analysis technique. Out of 40 items, a total of 28 items were

finally selected for the interest inventory. The reliability coefficient of the Purdue

Visualization of Rotations Test (PVRT) had been established by the test developer (Bodner

and Guay, 1997). However, to account for varied cultural and social context, a trial test was

carried out on the PVRT for determining its reliability coefficient. The PVRT was

administered on equivalent sample of ND1 Mechanical engineering technology students in

Kwara state polytechnics, Kwara state. Split Half reliability was computed to be .82 for

samples of 39. A trial test for determining the coefficient of stability of the Engineering

Graphics Achievement test (EGAT) was carried out using test re-test reliability technique.

The reliability coefficient of the EGAT was found to be .80 using Pearson Product Moment

correlation coefficient. Cronbach Alpha was used to determine the internal consistency of the

Engineering Graphics Interest Inventory items. The reliability coefficient computed for the

Engineering Graphics Interest inventory was found to be .91. The data collected were

analyzed using Mean, to answer the research questions while ANCOVA was used to test the

nine hypotheses formulated to guide this study.

99

Principal Findings of the Study

On the basis of the data collected and analyzed the following are the principal findings

of the study:

1. It was found out that AutoCAD 3-D technique is more effective than AutoCAD 2-D

technique in enhancing students’ achievement in engineering graphics. The effect was

found to be significant.

2. The study revealed that AutoCAD 3-D technique is more effective than AutoCAD 2-D

technique in improving students’ spatial ability in engineering graphics. The effect

was found to be significant.

3. AutoCAD 3-D technique is more effective in stimulating students’ interest in

engineering graphics than the 2-D technique but the effect was not found to be

significant.

4. It was found out that there was an effect of Gender on students’ spatial ability in

engineering graphics favouring boys. The effect was found to be significant.

5. The study revealed that there was an effect of Gender on students’ achievement in

engineering graphics favouring boys. The effect was found to be significant.

6. The study found out that there was an effect of Gender on students’ interest in

engineering graphics favouring boys. The effect was not found to be significant.


AutoCAD and their gender with respect to their mean scores on Engineering Graphics

Achievement Test


AutoCAD and their gender with respect to their mean scores on the Purdue

Visualization of Rotations Test.


AutoCAD and their gender with respect to their mean scores on the Engineering

Graphics Interest Inventory

Conclusions

Given the technological advancement which has occasioned ample use of Computer

Aided-Design packages such as AutoCAD for graphics design in the industry, the need to find

the best method of CAD to assist National Diploma students in mechanical engineering

technology to learn engineering graphics and improve their spatial ability is paramount. This

100

study found out that AutoCAD 3-D technique is more effective in improving students’ spatial

ability, achievement and interest in engineering graphics than AutoCAD 2-D technique. Also

the study revealed that, there was an effect attributable to gender on students’ spatial ability,

interest and achievement in engineering graphics. However, the study found out no significant

interaction effects of AutoCAD techniques and gender on spatial ability, achievement and

interest of National Diploma students in engineering graphics. This simply means that the

effectiveness of AutoCAD techniques on students’ spatial ability, interest and achievement in

engineering graphics does not depend on the levels of gender. Hence, irrespective of nature of

gender, learners will record improved performance in their spatial ability, interest and

achievement in engineering graphics when AutoCAD 3-D technique is employed for teaching

engineering graphics. These results therefore showed that AutoCAD 3-D technique is a viable

teaching method for engineering graphics. Furthermore, Computer Aided-Design packages

such as AutoCAD available today give technical teachers opportunity to engage students in

real world engineering graphics designing. It also gives students the opportunity to develop

valuable thinking skills in engineering graphics. Since, the use of CAD packages is clearly a

strategy that reflects modern business and industry practices and provides students with a

learnable tool for creative visualization; if AutoCAD 3-D technique is used for teaching

engineering graphics to the National Diploma students studying mechanical engineering

technology, the technicians trained will graduate with engineering graphics skills and spatial

ability needed for work in the present world of work.

Implications of the Findings

The findings of this study have implications for Technical Teachers, Curriculum

planners- National Board for Technical Education (NBTE), administrators of polytechnic,

Ministry of Education and government.

The study found out that AutoCAD 3-D technique is more effective in improving

students’ achievement, spatial ability and interest in engineering graphics. The implication of

this finding to curriculum planners is that they should develop appropriate curriculum that will

make provision for adoption of AutoCAD 3-D technique for teaching engineering graphics to

the National Diploma students. Another implication from this study is that such curriculum

developed will need to specify students’ and teachers’ activities that will aim at improving

students’ spatial ability in engineering graphics. In addition spatial skills training should be

integrated across the curriculum as this would increase students’ awareness of its importance

thus optimising the conditions of positive skills transfer

101

Having found out that AutoCAD 3-D technique is more effective for improving

students’ achievement, spatial ability and interest in engineering graphics, there is a need for

technical teachers to adopt this use of AutoCAD 3-D technique in the teaching of engineering

graphics to the National Diploma students. More importantly, since spatial ability is important

to problem solving and learning in engineering graphics, teachers need to place more

emphasis on the improvement of spatial skills in their engineering students with the use of

AutoCAD 3-D technique. Hence, there is a need for teachers of engineering graphics to place

more emphasis on students’ interaction with virtual objects and animation in AutoCAD 3-D

environment to give more opportunity for spatial skills improvement.

Moreover, one of the important finding emerged from this study is effect of gender on

spatial ability and achievement in engineering graphics favouring boys. This finding implied

that remedial lesson aimed at improving spatial skills of female students would be needed to

be organized by the school administrators as this would go a long way to improve their

achievement in engineering graphics. Besides, administrator should greatly appreciate the

need to constantly provides facilities such as computers and software packages as the needs

arise for the implementation of teaching engineering graphics with AutoCAD 3-D technique

Recommendations

Based on the findings of this study, the following recommendations are made:

1. Technical teachers of engineering graphics should adopt the use of AutoCAD 3-D

technique to the teaching of engineering graphics.

2. Technical teachers of engineering graphics should prepare their lessons in such a

way that students are allowed ample opportunity to interact freely with virtual

objects and animation in the AutoCAD 3-D space so as to improve their spatial

ability

3. National Board for Technical Education (NBTE) should consider review of

curriculum for engineering graphics with a view to incorporating AutoCAD 3-D

technique into the teaching of engineering graphics

4. AutoCAD 3-D technique should be a compulsory course for mechanical

engineering students in their first semester in the polytechnic with a view to

preparing them for the use of the technique in learning engineering graphics in the

second semester of ND I

5. Workshops, seminars and conferences should be organized by Ministry of

Education and administrators of polytechnics to enlighten technical teachers and

102

improve their knowledge and skills on the use of AutoCAD 3-D techniques for

improving students’ achievement and spatial ability in engineering graphics.

Suggestion for Further Study

From the findings of this study the following further research are suggested

1. AutoCAD 3-D technique use and curriculum revision needs of engineering graphics of

National diploma students in Nigeria Polytechnics

2. Adoption of AutoCAD 3-D techniques and skills improvement needs of engineering

graphics lecturers in the Nigeria polytechnics

3. Effects of AutoCAD 3-D technique and learning styles on spatial ability and

achievement of National Diploma students in engineering graphics

4. Effects of AutoCAD and Ability levels on spatial ability and achievement in

engineering graphics of National Diploma students.

103

References

Abdullahi, A. (1982). Science teaching in Nigeria. Ilorin: Atoto Publishing Company. Abonyi, S. O. (2005). Instrumentation in education research. In Ezeh, D. N. (Ed). What to

Write and How to Write. Enugu: Pearls and Gold. Aiken, L. R. (1979). Psychological testing and assessment (3rd edition). Boston: Allyn and

Bacon Inc. Ali, A. (1996). Introduction to research methodology in education. Obosi: Fulladu Publishers Alias, M. Black, T. R. & Gray, D. E. (2002). Effect of instruction on spatial visualization in

civil engineering students. Retrieved July 20, 2007. from http://www.ehlt.flinders.edu.au/education/iej/article/v3n1/Alias/papers.pdf

Alice, Y. (2001). AutoCAD tutorial 2 for release 2000. Retrieved July, 2007, from

http://www.ncsu.edu/project/graphicscourse/ge/acadtutt/acadtut2000/tutor2text.html Allen, A. D. (1999). Complex spatial skills: the link between visualization and creativity.

Retrieved June 25 2007, from http://www.scholar.lib.vt.edu/these/available/etd-03192000-17230059/unrestricted/complexspatialskills.pdf

Alonso, D., (1998). The effects of individual differences in spatial visualization ability on

dual-task performance. Retrieved June 20, 2007, from http://www.lap.umd.edu/lap/papers/Dissertations/Alonso_Dissertation_1998partIIhtml

Amanze, A. E. (1991). Welcome to computer science with basic programming language.

Enugu: Acena Publishers. Anene, G. U. (2005). Home economics and the academic performance of a child. Journals of

Home Economics Research, 6 (1), 99-103 Antherson, J. S. (2003). Learning and teaching: Intelligence. Retrieved February 20, 2004

from http//:www.dmu.ac.uk/-Jamesa/learningintellig.htm Ary, D. Jacob, L. C. & Razavieh, A. (2000). Introduction to research in education. New

York: Holt Rinehart and Winston Asilokun, B. A. (2006). Effects of AutoCAD on the performance of secondary school students

in technical drawing. Technology Education Journal. Vol 6(1). 196-204 Ausbel, D. P. (1963). The psychology of meaningful verbal learning. New York: Grume and

Stratton. Baenninger, M., & Newcombe, N. (1989). The role of experience in spatial test performance:

A meta-analysis. Sex Roles, 20(5/6), 327-344. Baldwin, T. K. & Hall-Wallance, M. (2001). Spatial ability development in geosciences.

Retrieved March 22, 2007, from http://www.sciends.com/research/spatialability.pdf Bandura, A. (1993). Perceived self-efficacy in cognitive development and functioning.

Educational Psychologist, 28(2), 117-148

104

Bannatyne, A. (2003). Multiple intelligences. Bannatyne Reading Program. Retrieved April

18, 2005, from http//:www.bannatynereadingprogram.com/BP12MULT.htm Basham, L. K. (2007). The effect of 3-dimensional CADD modeling software on the

development of spatial ability of ninth grade technology discovery students. Retrieved July 31, 2007, from http://www.etd.isu.edu/docs/available/etd-01192007-120328

Baskovich, B. W. (2001). J. Piaget’s genetic epistemology and the teaching of elementary

mathematics. Retrieved september 3, 2008, from http://www.eij.jcg.net Basu, O. K. (1997), Challenges of current social economical and technological development

and the need for reform/renovation in training of teachers in technical and vocational education. Retrieved March 20, 2006, from http://www.unevoc.unesco.org/publication/studiesilepdf.

Benbow, C. P. & Stanley, J. C. (1983). Sex differences in mathematical reasoning ability:

More fact. Science. 222, 1029-1031 Berry, J. W. (1966). Temne and Eskimo perceptual skills. International Journal of

Psychology, 1, 207-229. Bertoline, G. R., & Wiebe, E. N. (2003). Technical graphics communication (3rd Ed.). New

York: McGraw-Hill Bertoline, G. R., & Wiebe, E. N. (2005). Fundamentals of graphics communication (4th Ed.).

New York: McGraw-Hill Biehler, R. F. & Snowman, J. (1993). Psychology applied to teaching (7th Ed.). Boston: Bigge, M. L. & Shermis, S. S. (1998). Learning theory for teachers (6th Ed). New York:

Longman Bishop, A. (1980). Spatial abilities and mathematics education: A review. Educational Studies

in Mathematics, 11(3), 257-269 Blake, T. (1997). Motion in instructional media: Some subject-display mode interactions.

Perceptual and Motor Skills, 44, 975-985.

Bodner, G. M., & Guay, R. B. (1997). The Purdue visualization of rotations test. The Chemical Educator, 2(4), 1-18. Retrieved June 17, 2007, from http://www.chemeducator.org/papers/000204/24gb1897.pdf

Boersma, N. Hamlin, A. Sorby, S. (2004). Work in progress- Impact of a remedial 3-D visualization course on student performance and retention. Retrieved June 10, 2007, from http://www. ieeexplore.ieee.org/ie15/9652/30543/01408587.pdf

Boyle, E. A. Duffy, T and Donleavy, K (2003), Learning Styles and Academic Outome: The Validity and Utility of Vermants Inventory of Learning Style in a British Higher Education setting. British Journal of Educational Psychology. 73(2), 267 – 290.

105

Branoff, T. J. (1998). Coordinate Axes and Mental Rotation Tasks: A Dual-Coding Approach. Engineering Design Graphics Journal, 62(2), 16-34

Branoff, T. J. (2005). Three-dimensional constraint-based modelling: The big issues. Re-

examining the curriculum. Engineering Design Graphics Journal, 66(1), 5-10 Braukmann, J., & Pedras, M. J. (1993). A comparison of two methods of teaching

visualization skills to college students. Journal of Industrial Teacher Education, 30(2), 65-80.

Brewer, C. (2003). Computer in the classroom: How information technology can improve

conservation education. Retrieved March 22, 2007, from http://www.ibscre.dbs.ur.nt.edu/publication/Brewer-conBioarticle.pdf

Brewster, C. & Fager, J. (2000). Increasing student engagement and motivation: From Time-

on-task to homework. Retrieved June 10, 2007, from http://www.nwrel.org/request/oct00/testonly.html.

Bronitz, D. & Bonnie, B. (2002). AutoCAD 2002 complete. USA: BPB Publication Broussard, S. C. (2002). The relationship between classroom motivation and academic

achievement in first and third graders. Retrieved August 20, 2005, from http://www.etd.isu.edu/docs/available/etd.1107102-185505/unrestricted/Broussard-theses.pdf

Bryan, L. (1997). How designer think. London: Biddeg Limited. Bui, H. L. T. (2006). Translating AutoCAD Architectural drawing into rapid prototyping

compatible drawing. Retrieved July 25, 2007, fro http://www.asceditor.usm.edu/ARCHIVES/2006/CERTORwinek%2006-2500.htm

Burin, D. I., Delgado, Y. G., & Prieto, A. R. (2000). Solution strategies and gender

differences in spatial visualization tasks. Retrieved June 17, 2007, from http:// www.uv.esrevispsi/article53.00/buri5.pdf

Christopher, J. D. (1990). AutoCAD cook book. Canada: John Wiley Publishers. Chukwu, A. (2002). Promoting students’ interest in mathematics using local games.

International Journals of Arts and Technology Education. 2(1), 54-56. Cohen, C. A., Hegarty, M., Keehner, M., & Montello, D. R. (2003, July). Spatial ability in the

representation of cross sections. Poster presented at the Annual Conference of the Cognitive Science Society Conference Boston, MA. Retrieved March 18, 2005, from http:www.princeton.edu/~jjg/nsf_report.html

Columbia Encyclopedia (2005). Pearson Education (6th Edition). Retrieved April 24, 2007,

from http://www.infoplease.com. Condor, O. O. (2007). Integrating design in engineering graphics courses using feature-based,

parametric solid modelling. Retrieved January 28, 2008, from http//:www.cosmoc.org/.html

106

Cotton, K. (2001). Computer-assisted instruction. Retrieved July 20, 2007 from http://www. nwrel.org/scpd/sirs/Computer-AssistedInstruction.htm

Croft, F. M., Meyers, F. D., Boyer, E. T., Miller, M. J., & Demel, J. T. (1989). Engineering

graphics. New York: Wiley. Demmert, G. W. (2001), Improving Academic Performance among native American Students:

A Review of the Research Literature. Retrieved March 20, 2006 from http://www.aor.com/pdf

Deno, J. A. (1995). The relationship of previous experiences to spatial visualization ability.

Engineering Design Graphics Journal, Autumn, 5-17 Epunam, A. D. (1999). Influence of school environmental variables on academic performance

as perceived by students. Unpublished M.Ed thesis. University of Nigeria, Nsukka Federal Republic of Nigeria (2004), National Policy on Education. Lagos; NERDC. Finkelstein, E. (2002). AutoCAD® 2002 bible. New York: Hungry Minds Gall, M. D., Gall, J. P. & Borg, W. R. (2007). Educational research: An introduction. Boston:

Pearson Educational Inc. Gillespie, W. H. (1995). Using solid modeling tutorials to enhance visualization skills.

Dissertation Abstracts International, 56, 11A. (UMI No. AAI9606359) Godfrey, G. S. (1999). Three-dimensional visualization using solid-model methods: A

comparative study of engineering and technology students. Retrieved June 25, 2007, from http://www.uas.edu/theses/available/etd-000872003 110107/unrestricted/etd.pdf

Gottfried, A. E. (1990). Academic intrinsic motivation in young elementary school children.

Journal of Educational Psychology, 82(3), 525-538. Gutierrez, A (1996). Visualization in 3-dimensional geometry. Psychology of Mathematics

Education. 1, 3-19 Hallak, J and poisson, M (2000). Education and Globalization: Learning to live together. In

UNESCO’S Globalization and living together: The challenges for education content in ASIA. France: UNESCO

Hart, W. J. (2003). Effect of computer animation instruction on spatial visualization

performance. Retrieved June 25, 2007, from http://www.lib,nisu.edu/theses/available/etd-04042003-110107/unrestricted/etd.pdf

Harter, S. (1981). A new self-report scale of intrinsic versus extrinsic orientation in the

classroom: motivational and informational components. Developmental Psychology, 17, 300-312.

Hays, T. A. (1996). Spatial abilities and the effects of computer animation on the short-term

and long-term comprehension. Journal of Educational Computing Research, 14(2), 139-155.

107

Hegarty, M., & Waller, D. (2005). A dissociation between mental rotation and perspective-taking spatial abilities. Intelligence, 32, 175-191

Hilgard, E. R., Atkinson, R. L., and Atkinson, R. C. (1975). Introduction to psychology (7th

Ed). New York: Harcourt Brace-Jovanovich, inc. Hornby, S. A. (2000). Oxford advance learner’s dictionary. Ibadan: Oxford University Press Hubona, G. S., & Shirah, G. W. (2004). The gender factor: Performing visualization tasks on

computer media. Retrieved May 22, 2008 from http:/www./myschoolnet.ppk.kpm.my/pl/panduan%20sijil%20terbuka.pdf.

Hutchinson, J. (2002). Design not drafting. Retrieved February 16, 2008, from

http://www.millersville.edu/-itec/htm International Labour Organization (ILO) (2003). Core work skills. Retrieved May 20, 2007,

from http://www.ilo.org/public/english/employment/skills/tpp/index.htm Isaac, A. R., & Marks, D. F. (1994). Individual differences in mental imagery experience:

Developmental changes and specialization. British Journal of Psychology, 85(4), 479-500.

Jensen, C. & Helsen, D. J. (1996). Fundamentals of engineering drawing (4th edition). New

York: McGraw-Hill. Johnson, J. E., (1991). Can spatial visualization skills be improved through training that

utilizes computer generated visual aids? Retrieved April 16, 2007 from http://www.ilman.org/0009874/1991-GeomEduspatialability.pdf

Jonassen, D. H. (2000). Toward a design theory of problem solving. Educational Technology

Research and Development, 48(4), 63-85. Jones, K., & Bills, C. (1998). Visualization, imagery and the development of geometrical

reasoning. Geometry Working Group. Retrieved April 10, 2005 from http:// www.soton.ac.uk/~dkj/bsrlmgeom/reports/K_Jones_et_al_June_1998.pdf

Kamara, J. M. (2006). Integration of virtual reality within the bult environment curriculum.

Retrieved September 18, 2007, from http://www.itcon.org/2006/23 Kaufmann, H., Steinbugl, K., Dunser, A., & Gluck, J. (2005). General training of spatial

abilities by geometry education in augumented reality. Retrieved April, 2007 from http://www.hitlabnz.org/fileman-store/2005-GeomEduspatialability.pdf

Keller, B. & Hart, E. (2002). Improving students’ spatial visualization skills and teacher’s

pedagogical content knowledge by using on-line curriculum-embedded applets. Retrieved July 20, 2007, from http://www.clrn.org/search/detail.cfm?section=abstract&elrid=2803

Kinsey, B. (2003). Design of a cad integrated physical model rotator. Retrieved May 19, 2007

from http//:www.ni.com/academic/journal_asee.htm

108

Koch, D. S. (2006). The effects of solid modeling and visualization on technical problem solving. Retrieved July 20, 2007, from http://www.scholar.lib.vt.edu/theses/available/etd05192006142531/unrestricted/kochDissertation.pdf

Kushman, J. W., Sieber, C., & Harold, K. P. (2000). This isn’t the place for me: School

dropout. In D. Capuzzi & D. R. Gross (Eds.), Youth at risk: A prevention resource for counselors, teachers, and parents (3rd Ed). Alexandria, VA: American Counseling Association.

Lahav, O. (2006). CyberPsychology and Behavior. Retrieved May 10, 2007 from

http://www.liebertonline.com/doi/pdfplus/10.1089/cpb2006.9.174 Lemut, E. Pedemonte, B. & Robotti, E. (2000). AutoCAD: An artifact for mediating

geometric knowledge. Retrieved April 20, 2007, from http://itip.org/con2000/icent2000/icent//-05pdf

Linn, M. C., & Petersen, A. C. (1985) Emergence and characterization of sex differences in

spatial ability: A metaanalysis, Child Development, 56, 1479-1498. Lohman, D. F. (1993). Spatial ability and g. Retrieved July 28, 2007, from

http://www.faculty.education.uiowa.edu/dlohman/pdf/Spatial-Ability-and-G.pdf Love, R. K. (2004). Animations and learning: Value for money? Educational Researcher, 18,

17-19. Lowrie, T. (1994). Developing talented children's mathematical ability through visual and

spatial learning tasks Retrieved June 25 2007 from http://www.aare.edu.au/92pap/lowrt92487

Maccoby, E. E., & Jacklin, C. N. (1974). The Psychology of sex differences. Stanford, CA:

Stanford University Press. Mackenzie, D. S., & Jansen, D. G. (2005). Impact of multimedia computer-based instruction

on student comprehension of drafting principles. Journal of Industrial Teacher Education, 35(4), 61-82.

Maier , P. H. (2005). Spatial geometry and spatial ability-how to make solid geometry solid.

Retrieved September 10, 2007, from http:// www.leoe.com/dio/pdf. Mann, R. L. (2005). The identification of gifted students with spatial strengthens: An

exploratory study. Retrieved July 20, 2007, from http://www. gifted.uconn.edu/siegle/Disertation/Rebecca%20Mann.pdf

Mantovani. F. (2001). VR learning: potential and challenges for the use of 3D environments

in education and training. Towards CyberPsychology: Mind, Cognitions and Society in the Internet Age, Amsterdam: IOS Press.

Mayton, G. B. (1991). Learning dynamic process from animated visuals in microcomputer-

based instruction. Retrieved July 20, 2007, from http://.www.eric.edu.gov/record

109

McCarty, E. M. (2007). Spatial abilities. Retrieved October 25, 2007 from http://www. social.jrank.org/pages/604/spatial-abilities.htm

McGee, M. (1979). Human Spatial Abilities: Sources of Sex Differences. New York: Holt,

Rinehart and Winston/BS, Inc. Medina, A. C. Gerson, H. B. P. & Sorby, S. A. (2000). Identifying gender difference in the 3-

D visualization skills of engineering students in Brazil and in the United States. Retrieved July 25, 2007 from http://www. iwitts.com/html

Mitchell, J. V. (1992). Interrelationships and predictive efficacy for indices of intrinsic,

extrinsic, and self-assessed motivation for learning. Journal of Research and Development in Education, 25(3), 149-155.

Mohler, A. A. (2006). Using interactive multimedia technologies to improve student

understanding of spatially-dependent engineering concepts. Retrieved July 10, 2007, from http://www.eg.org/pub/Histeng/People/Monge/Mohler.pdf

Moore, D. K. (1999). Classroom Teaching Skills. New York: McGraw Hikk Companies. Moyer, P. S., Bolyard, J. J., & Spikell, M. A. (2001). Virtual manipulatives in the K-12

classroom. Paper presented at the International Conference on New Ideas in Mathematics Education, August 19-24, 2001, Palm Cove, Queensland, Australia. Retrieved July 25, 2007 from http://www. Clifs .com/html

Munro, J. (1999). Mathematics underachievers learning spatial Knowledge. Retrieved

September 3, 2008, from http://www.daneprairie.comi National Board for Technical Education (2003). Mechanical engineering curriculum and

course specification. National Board for Technical Education, kaduna, Revised Curricular for Technical Colleges and Polytechnics [CD]

Nemeth, B & Hoffmann, M. (2006). Gender difference in spatial visualization among

engineering students. Retrieved June 23, 2007, from http://www.ektf.hu/tanszek/matematicka/ami

Newcombe, N. S., & Huttenlocher, J. (2000). Making space: The development of spatial

representation and reasoning. Retrieved July 25, 2007 from http://www. mtpress.mitedu/026214069

Newcomer, J. L., Raudebaugh, R. A., McKell, E. K., & Kelley, D. S. (1999). Visualization,

freehand drawing, solid modeling, and design in introductory engineering graphics. Retrieved October 20, 2007 from http://www.fie.engrng.pitt.edu/fie99/papers/1006.pdf

Ngwoke, D. U. (2004). School Learning theories and applications. Enugu: Magnet Business

Enterprise. Ngwoke, D. U. & Eze, U. N. (2004). Developmental psychology and education. . Enugu:

Magnet Business Enterprise. Nordvik, H., & Amponsah, B. (1998). Gender differences in spatial abilities and spatial

activity among university students in egalitarian educational system. Sex Roles, 38(11/12), 1009-10023

110

Nwachukwu, T. A (1995). Psychology of learning. Enugu: De Sandex (Nig) Ltd. Ogwo, B. A. & Oranu, R. N. (2006). Methodology in informal and nonformal

technical/vocational education. Nsukka: University if Nigeria press Ltd Ogwo, B. A. (2004) Functionality vocational education in Nigeria public schools: Examining

some Policy Paradigms. In Uzodimma, C. U (Ed), Functionality of Education in Nigeria: Issues, Problems and Concern. Enugu. The Academic Forum for the Inter-disciplinary Discuss (TAFID).

Okorie, J. U. (2000). Developing Nigeria Workforce. Calabar: page Envirous Publishers. Okoro, O. M. (1994). Measurement and evaluation in education. Uruowulu-obosi: Pacific

publishers. Okpara, E. N. (1994). Domains and types of educational objectives. In Offorma, G. C. (Ed).

Curriculum Implementation and Instruction. Onitsha: Uni-World Educational Publishing (NIG) LTD

Olkun, S. (2003). Making connections: Improving spatial abilities with engineering drawing

activities. International Journal of Mathematics Teaching and Learning. Retrieved July 27, 2007 from http://www.cimt.plymouth.ac.uk/journal/default.htm

Omura, G. (2003). Mastering AutoCAD 2004 and AutoCAD LT 2004. USA: BPB Publications Opara, M. F. (2002). Can self-regulation process promote sustainable development through

enhancement of students’ interest in qualitative chemical analysis? In Akale, M. A (Ed) Science, Technology and Mathematics education for Sustainable development in Africa. Proceedings of the 43rd Annual Conference and Inaugural Conference of (CASTME) Africa.

Osberg, K. (1995). Spatial cognition in the virtual environment. Retrieved June 10, 2007,from

http://www.hilt.washinton.edu/projects/education/puzzle/spatial-cognition.html Osberg, K. M., Winn, W., Rose, H., Hollander, A., Hoffman, H., & char, P., (1997). The

effect of having grade seven students construct virtual environments on their comprehension of science. Retrieved September 18, 2007, from http://www.hilt.washinton.edu/publications/r-97-19

Paris, K. (1998). Critical issues: developing an applied and integrated curriculum. Retrieved

March 20, 2006, from http://www.ncrel.org/sdrs/areas/curr/htm Petersen, A. (1985). Human spatial abilities. New York. Preger Pittalis, M., Mousoulides, N., & Christou, C. (2002). Spatial ability as a predictor of geometry

ability. Review of Educational Research, 65, 22-50 Postma, A., Izendoorn, R., & De Haan, E. H. F. (1998). memory. Brain and Cognition, 36,

334-345.

111

Potter, C., & van der Merwe, E. (2001). Spatial ability, visual imagery and academic performance in engineering graphics. . Retrieved March 10, 2007 from http://www.scholor.liib.vt.edu/ejournals/JUER/v27nl/potters:html.

Presmeg, N. (1992). Prototypes, metaphor, metonymies and imaginative rationality in high

school mathematics. Educational Studies in Mathematics, 23, 595-610 Proffitt, D. R., & Kaiser, M. K. (1986). The use of computer graphics animation in motion

perception research. Behavior Research Methods, Instruments, & Computers, 18(6), 487-492.

Qureshi, M. A. (1997). Recent innovations in the training of teachers/trainers in technical and

vocational education in Asia and the Pacific. Retrieved March 20, 2006., from http://www.unevoc.unesco.org/publication/studiesilepdf.

Rafi, A., Samsudin, K. A., & Said, C. S. (2008). Training in spatial visualization: The effects

of training method and gender. Educational Technology and Society. 11(3), 127-140 Reifschneider, L. (2000). Teaching design for manufacturability with computer-aided

analysis. Retrieved February 10, 2008 from http://www.nait.or/ejournalsreifschneider:html

Reynolds, A. M., & Wheatley, G. H. (1999). Image maker: Developing spatial sense.Teaching

Children Mathematics, 5(6), 374-378. Rivkin, S. G., Hanushek, E. A & Kain, J. F., (2000). Teachers, schools and academic

achievement. Retrieved October 10, 2007, from http://www.mccsc.edu/-curriculum/teacher,%20schools,%20and %20achievement.pdf

Robichaux, R. R. (2003). The improvement of spatial visualization: A case study. Journal of

Integrative Psychology, 4(2). Retrieved June 20, 2007 from http://www.integrativepsychology.org/articles/vol2_article3.htm

Rojewski, W. J. (2002). Preparing the workforce of tomorrow: A conceptual framework for

career and technical education. Journal of Vocational Education Research. Retrieved March 10, 2006 from http://www.scholor.lib.vt.edu/ejournals/JUER/v27nl/rojewski:html.

Scribner S. A., & Anderson M. A. (2005). Novice drafter’ spatial visualization development:

Influence of instructional methods and individual learning styles. Retrieved June 18, 2007, from http://www.scholar.lib.edu/ejournals/JITE/v42n2/pdf/scribner.pdf

Shell, T. J. (1986). Cognitive conception learning. Review of Educational Research, 56 (4),

41-46. Shubbar, K. E. (1990). Learning the visualization of rotations in diagrams of three

dimensional structures. Research in Science & Technological Education, 8(2), 145-1554.

Sjolinder, M. (1998). Spatial cognition and environmental descriptions. Towards a

Framework for Design and Evaluation of Navigation in Electronic Spaces. Retrieved October 31, 2007, from http://www.sics.se/humle/projects/persona/web/persona.html

112

Smith, G. G. (2001). Interaction evokes reflection: Learning efficiency in spatial visualization.

Interactive Multimedia: Electronic Journal of Computer-Enhanced Learning. Retrieved May 23, 2005 from http://imej.wfu.edu/articles/2001/2/05/index.asp

Smith, M. K.( 2002). Howard gardner, multiple intelligences and education. Retrieved June

20 2007, from http://www.infed.org/thinker/gardner.htm Sorby, S. A., & Baartmans, B. J. (2000). The development and assessment of a course for

enhancing the 3-D spatial visualization skills of first year engineering students. Journal of Engineering Education, 89(3), 301-307.

Steed, M. (2001, November). 3-D visualization: Using 3-D software to represent curricular

concepts. Learning & Leading with Technology, 29(3), 14-20. Steward, P. & Aiken, D. (1982). Teaching physics creatively in secondary schools. London:

Wiley and Co. Strom, B. (2004). Student achievement and birthday effects. Retrieved August 20, 2007, from

http://www.ksg.harvard/pepg/pdf/events/munich/PEPG-04-24strom.pdf Strong, S. & Smith, R. (2002) spatial visualization: Fundamentals and trends in engineering

graphics. Journal of Industrial Technology. Retrieved june 10, 2007 from http://www.nail.org/jit/Article/Strong122001.pdf

Sueoka, H. Shimizu, S. &Yokosawa, H. (2001). The use of internet technology for the

development of 3-D spatial visualization. Retireved July 23, 2007, from http://www.eecs.kumamoto-u.acjp/ITHET01/ptoc/126.pdf

Summerfield, M., & Youngman, M. (1999). The relationship between personality and

attainment in 16–19 year old students in a sixth form college: II. Self-perception, gender and attainment. British Journal of Educational Psychology, 69, 173–187.

Tartre, L. A. (1990). Spatial orientation skill and mathematical problem solving. Journal for

Research in Mathematics Education, 21(3), 216-229 Texas Academic & Management Consult (2000). AutoCAD made easy. Lagos:Authour Thomas, D. A. (1996). Enhancing spatial 3-dimensional visualization and rotational ability

with 3-dimensional computer graphics.. In Scribner S. A., & Anderson M. A. (2005). Novice drafter’ spatial visualization development: Influence of instructional methods and individual learning styles. Retrieved June 18, 2007, from http://www.scholar.lib.edu/ejournals/JITE/v42n2/pdf/scribner.pdf

Tremblay, L. (2004). Spatial orientation differences between male and female .Retrieved

October 25, 2007 from http:// www.sexes.eurekalert.org/punews.php Tuckman, B. W. (1999). Conducting educational research (5th ed.) Belmont, CA: Wadsworth

113

Uka, N. (1981). The learning process. In Poroye, M. T. (Ed) Essentials of foundations of educational thought and practice. Lagos: NERC

Ukoha, U. A. & Eneogwe, U. N. (1996). The instructional process. In Ogwo, B. A. (Ed). Curriculum Development and Educational Technology. Markudi: Onaivi Publishing Co. Ltd

Ulman, D. G. Stephen, W. & Craig, D. (1990). The importance of drawing in the mechanical

design process. Retrieved July 20, 2007, from http://www.web.engr.oregun.edu/-ulman/drwg.htm

UNESCO (2002). Information and communication technology in teacher education. Retrieved

may 10, 2006 from http://www.unesdoc.org/images/0012/001295/129533epdf UNESCO & ILO (2002). Technical and vocational education and training for the twenty–first

century. Paris: UNESCO. Uwameiye, R. & Osunde, A. U. (2005). Analysis of enrolment pattern in Nigerian

polytechnics’ academic programmes and gender imbalance. Journal of Home Economics research 6 (1), 150-155

Velez, M. C., Silver, D., & Tremaine, M. (2005). Understnading visualization through spatial

ability differences. Retrieved June 20, 2007, from http://caip.rutgerser.edu/_matiscv/publications/vis05.pdf

Voyer, D., Voyer, S., & Bryden, P. (1995). Magnitude of sex differences in spatial abilities: A

meta-analysis and consideration of critical variables. Psychological Bulletin, 117 (2), 250 270.

Wade, C. & Tavris, C. (1993). Psychology (3rd edition). New York: Harper Collins

Publishing. Whelan, P. (1994). AutoCAD assignment. Ireland: Stanley Thornes (Publishers) Ltd Wikipedia (2007) AutoCAD. Retrieved June 20, 2007, from

http://www.en.wikipedia.org/wiki/AutoCAD Wiley, S. E. (1990). Computer graphics and the development of visual perception in

engineering graphics curricula, Engineering Design Graphics Journal, 54(2), 39-43. Williamson, V. M., & Abraham, M. R. (1995). The effects of computer animation on the

particulate mental models of college chemistry students. Journal of Research in Science Teaching, 32(5), 521-534.

Winn, W., Hofman, H.,Hollander, A., Osberg, K., Rose, H., & Char, P. (1997). The effect of

student construction of virtual environments on the performance of high-and low-ability students. Retrieved September 18, 2007, from http://www.hilt.washinton.edu/publications/r-97-6

Yarwood, A. (1996). An introduction to AutoCAD LT for windows 95. England: Longman Yusuff, K. A. (2005). Technical drawing 1. Ibadan: OCITEC Printing Company.

114

Yusuff, K. A. (2006). Introduction to information, communication and computer technology (4th edition). Ibadan:Freedom press.

Zacks, J. M., Mires, J., Tversky, B., & Hazeltine, E. (2000). Mental spatial transformations of

objects and perspective. Spatial Cognition and Computation, 2(4), 315-332. Retrieved August 20, 2007, from http://www.wexler.free.fr/library/files/zacks%20(2001)%20mental.pdf

115

APPENDIX A

AUTOCAD TECHNIQUES, ACTUAL TREATMENT TO THE STUDENTS AND THE DEPENDENT VARIABLES COVERED

Two-Dimensional Technique

Element Manipulation Spatial Ability

Interest Achievement

Use of absolute coordinate

Specify 0,0 using the world Coordinate system (WCS) (Spatial ability) to locate a point (Achievement) for a point to appear on the graphics display screen (Interest)

√

√

√

Draw horizontal line repeatedly given specific measurement (Achievement) by specifying (x,y) 2-D coordinate to move a distance of given measurement along the X-axis from the origin 0,0 (Spatial ability) for the line to appear on the graphics display screen in different colours (Interest)

√

√

√

Draw vertical line repeatedly given specific measurement (Achievement) by specifying (x,y) 2-D coordinate to move a distance of given measurement along the y-axis from the origin 0,0 (Spatial ability) for the line to appear on the graphics display screen in different colours (Interest)

√

√

√

Draw circle repeatedly given specific radius and locating centre point (Achievement) by specifying (x,y) 2-D coordinate (Spatial ability) for the circle to appear automatically on the graphics display screen in different colours (Interest)

√

√

√

Construct objects such as rectangle and other two-dimensional objects repeatedly given specific length and width (Achievement) by specifying (x,y) 2-D coordinate to move a distance of given measurement along the X- and Y- axes from the origin 0,0 (Spatial ability) for the rectangle to appear on the graphics display screen in different colours (Interest)

√

√

√

Use of relative coordinate Draw horizontal line repeatedly given specific measurement (Achievement) by specifying @(x,y) 2-D coordinate to move a distance of given measurement along the X-axis from a previously defined coordinate (Spatial ability) for the line to appear on the graphics display screen in different colours desired (Interest)

√

√

√

Draw vertical line repeatedly given specific measurement (Achievement) by specifying @(x,y) 2-D coordinate to move a distance of given measurement along the y-axis from a previously defined coordinate (Spatial ability) for the line to appear on the graphics display screen in different colours (Interest

√

√

√

Construct objects such as rectangle and other two-dimensional objects repeatedly given specific length and width (Achievement) by specifying @(x,y) 2-D coordinate to move a distance of given measurement along the X- and Y- axes from a previously defined coordinate (Spatial ability) for the rectangle to appear on the graphics display screen in different colours (Interest)

√

√

√

116

Use of polar coordinate Draw line repeatedly at different angles given specific measurement (Achievement) by specifying @(distance<angle) e.g @50<60, 2-D coordinate where the length of the line is 50mm long and is inclined at angle of 60 degrees to the previously defined coordinate to move a distance of given measurement along the X-axis from a previously defined coordinate (Spatial ability) for the line to appear on the graphics display screen in different colours (Interest)

√

√

√

Use of absolute, relative and polar coordinate

Construct a block in isometric projection given a specific dimension (Achievement) by specifying coordinate in absolute (x,y); relative @ (x,y) and polar @(distance<angle) in on 2-D space to move a distance of the given dimensions on the X- and Y-axes (Spatial ability) for the block to appear on the graphics display screen with a desired colour (Interest)

√

√

√

Use of command (1). Draw lines, circle, rectangle, Ellipse repeatedly (Spatial ability) by specifying the dimensions (Achievement) with the use of line, rectangle, circle command to generate the shapes automatically (Interest).

√

√

√

(2). Rotate objects repeatedly (Spatial Ability) with rotate tool bar command to automatically rotate the object (Interest) given a specific angle of rotation (Achievement).

√

√

√

(3). chamfer shapes repeatedly (Spatial ability) given a specific angle of chamfer (Achievement) using chamfer tool bar command to automatically chamfer the intended shape (Interest)

√

√

√

(4). extend lines, trim lines and offset lines repeatedly (Spatial ability) given a specific tolerant measure (Achievement) with modifying tool bar commands to show the extension trim and offsets (Interest)

√

√

√

(1) Construct a three-dimensional block from a given front view of the block (Achievement) by converting the front view (2-D object to a block (3-D) object (Spatial ability) using solid modeling extrude command to execute the conversion automatically (Interest) (2) convert the block to virtual object (Spatial ability)

√

√

√

Construct orthographic projection of a block (Achievement) by converting the block (3-D object) to plan, front and end views (2-D object) (Spatial ability) using solview and soldraw command to execute the conversion automatically (Interest)

√

√

√

Construct an auxiliary view of a block (Achievement) from one of the multview of the object (Spatial ability) using auxiliary command to execute the conversion automatically (Interest)

√

√

√

Construct section view of a block (Achievement) using section command to execute the conversion automatically (Interest)

√

√

117

Three-Dimensional technique Element Manipulation Spatial

Ability Interest Achievement

Use of absolute coordinate

Specify 0,0,0 using the world Coordinate system (WCS (Spatial ability) to locate a point (Achievement) for a point to appear on the graphics display screen (Interest)

√

√

√

Draw horizontal line repeatedly given specific measurement (Achievement) by specifying (x,y,z) 3-D coordinate to move a distance of given measurement along the X-axis from the origin 0,0,0 (Spatial ability) for the line to appear on the graphics display screen in different colours (Interest)

√

√

√

Draw vertical line repeatedly given specific measurement (Achievement) by specifying (x,,y,z) 3-D coordinate to move a distance of given measurement along the y-axis from the origin 0,0,0 (Spatial ability) for the line to appear on the graphics display screen in different colours (Interest)

√

√

√

Draw circle repeatedly given specific radius and locating centre point (Achievement) by specifying (x,y,z) 3-D coordinate (Spatial ability) for the circle to appear automatically on the graphics display screen in different colours (Interest)

√

√

√

Construct objects such as rectangle and other two-dimensional objects repeatedly given specific length and width (Achievement) by specifying (x,y,z) 3-D coordinate to move a distance of given measurement along the X- , Y- and Z- axes from the origin 0,0,0 (Spatial ability) for the rectangle to appear on the graphics display screen in different colours (Interest)

√

√

√

Use of relative coordinate

Draw horizontal line repeatedly given specific measurement (Achievement) by specifying @(x,y,z) on 3-D coordinate to move a distance of given measurement along the X-axis from a previously defined coordinate (Spatial ability) for the line to appear on the graphics display screen in different colours (Interest)

√

√

√

Draw vertical line repeatedly given specific measurement (Achievement) by specifying @(x,y,z) 3-D coordinate to move a distance of given measurement along the y-axis from a previously defined coordinate (Spatial ability) for the line to appear on the graphics display screen in different colours (Interest

√

√

√

Construct objects such as rectangle and other two-dimensional objects repeatedly given specific length and width (Achievement) by specifying @(x,y,z) 3-D coordinate to move a distance of given measurement along the X- ,Y- and Z axes from a previously defined coordinate (Spatial ability) for the rectangle to appear on the graphics display screen in different colours (Interest)

√

√

√

Use of Spherical Coordinate

Draw line repeatedly at different angles given specific measurement (Achievement) by specifying @(distance<angle,<angle) e.g @50<60<30, 3-D coordinate where the length of the line is 50mm long and is inclined at angle of 60 degrees in XY plane and 30 degrees from XY plane to the previously defined coordinate to move a distance of given measurement from a previously defined coordinate (Spatial ability) for the line to appear on the graphics display screen in different colours (Interest)

√

√

√

Use of absolute, Construct a block in isometric projection given a

118

relative and spherical coordinate

specific dimension (Achievement) by specifying coordinate in absolute (x,y,z); relative @ (x,y,z) and spherical @(distance<angle<angle) on 3-D space to move a distance of the given dimensions on the X-, Y-axes and Z (Spatial ability) for the block to appear on the graphics display screen with a desired colour (Interest)

√

√

√

Use of command (1). Draw lines, circle, rectangle, Ellipse repeatedly (Spatial ability) by specifying the dimensions (Achievement) with the use of line, rectangle, circle command to generate the shapes automatically (Interest).

√

√

√

(2). Rotate objects repeatedly (Spatial Ability) with rotate tool bar command to automatically rotate the object (Interest) given a specific angle of rotation (Achievement).

√

√

√

(3). chamfer shapes repeatedly (Spatial ability) given a specific angle of chamfer (Achievement) using chamfer tool bar command to automatically chamfer the intended shape (Interest)

√

√

√

(4). extend lines, trim lines and offset lines repeatedly (Spatial ability) given a specific tolerant measure (Achievement) with modifying tool bar commands to show the extension trim and offsets (Interest)

√

√

√

Use of command (1). Rotate View points to a object repeatedly in 3-D space by specifying angles of rotation IN XY plane from X axis and specific degree from the XY plane i.e Z- axis (Spatial Ability) to view the objects Top, Front, and End View (Achievement) using Vpoint Command to change the view point automatically (Interest)

√

√

√

(2). Rotate viewpoint for angle of 300 degree IN XY plane from X axis and 35 degree from the XY plane (Spatial Ability) to regenerate the TOP view, FRONT view and Right Side View in 2-D to 3-D objects (Achievement) using the vpoint command to change the view point automatically (Interest)

√

√

√

(1) Construct a three-dimensional block from a given front view of the block (Achievement) by converting the front view (2-D object to a block (3-D) object (Spatial ability) using solid modeling extrude command to execute the conversion automatically (Interest) (2) render the block constructed repeatedly to convert the object to a virtual object (Spatial ability)

√

√

√

(3). Interact with virtual objects by rotating objects in a 3-D space repeatedly (Spatial Ability) using 3-D continuous orbit command to view the model as it rotates (Interest) relative to the 3-dimensional coordinate (X, Y, Z) orientation (Achievement)

√

√

√

interact with virtual objects by rotating objects in a 3-D space repeatedly using 3-D orbit through panning, twisting, rotating, and rolling of the virtual objects to provide multi-point viewing relative to X,Y,Z coordinate system (Spatial Ability, and Interest)

√

√

Construct orthographic projection of a block (Achievement) by converting the block (3-D object) to plan, front and end views (2-D object) (Spatial ability) using solview and soldraw command to execute the conversion automatically (Interest)

√

√

√

119

Construct an auxiliary view of a block (Achievement) from one of the multview of the object (Spatial ability) using auxiliary command to execute the conversion automatically (Interest)

√

√

√

Construct an section view of a block (Achievement) using section command to execute the conversion automatically (Interest)

√

√

(4). Subtract and add shapes together to construct models with round hole and stepped block (Spatial Ability) given a specific dimension (Achievement) using subtract and addition commands (Interest)

√

√

√

Date post:	03-Aug-2020
Category:	Documents
Upload:	others
View:	5 times
Download:	0 times

JIMOH, JELILI ADEBAYO - University of Nigeria, Nsukka · JIMOH, J. A. Dr. B. A. OGWO CANDIDATE...

Documents