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““A REVIEW ON EXPERIMENTAL DESIGNS”A REVIEW ON EXPERIMENTAL DESIGNS”

PRESENTING BY,PRESENTING BY,Ms. SONALI B. DIWATEMs. SONALI B. DIWATE

GUIDED BY,GUIDED BY,PROF. N. KULKARNIPROF. N. KULKARNI

MODERN C.O.P.,MOSHI, PUNE-412105 MODERN C.O.P.,MOSHI, PUNE-412105

04/10/23

To Review and Study the To Review and Study the Experimental DesignsExperimental Designs

OBJECTIVEOBJECTIVE

1. To collect the information about Experimental Designs.1. To collect the information about Experimental Designs.

(Literature Survey)(Literature Survey)

2.To study the importance of Experimental Designs.2.To study the importance of Experimental Designs.

3.To understand the basic terminologies related to Experimental Designs3.To understand the basic terminologies related to Experimental Designs

4. To explain the types of Experimental Designs.4. To explain the types of Experimental Designs.

5. Summarization of the information.5. Summarization of the information.

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CONTENTS…..CONTENTS…..

1. AIM AND OBJECTIVE1. AIM AND OBJECTIVE

2.INTRODUCTION TO EXPERIMENTAL DESIGNS2.INTRODUCTION TO EXPERIMENTAL DESIGNS

3. IMPORTANCE OF EXPERIMENTAL DESIGNS3. IMPORTANCE OF EXPERIMENTAL DESIGNS

4.BASIC TERMINOLOGIES RELATED TO EXPERIMENTAL DESIGNS4.BASIC TERMINOLOGIES RELATED TO EXPERIMENTAL DESIGNS

5. TYPES OF EXPERIMENTAL DESIGNS5. TYPES OF EXPERIMENTAL DESIGNS

6. SUMMERY6. SUMMERY

7. CONCLUSION7. CONCLUSION

8. BIBLIOGRAPHY8. BIBLIOGRAPHY

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INTRODUCTION TO EXPERIMENTAL DESIGNSINTRODUCTION TO EXPERIMENTAL DESIGNS[]

An EXPERIMENTAL DESIGN consists of a description of how a particular

hypothesis can be experimentally tested.

The strategy that directs the researcher in planning & implementing the

study in way that is most likely to achieve the intended goal.

IMPORTANCE OF EXPERIMENTAL DESIGNS

• It helps in bioavailability & bioequivalence studies.

• It helps in determining the plasma drug level in different formulations.

• It is used to ensure the clinical performance of different products.

• It is important when researcher want to study the effects of two or more

independent variables at the same time.

• It represent the complexity which occurs during real experiment accurately.

• It gives idea about variations due to time effect. 404/10/23

What do these studies tell you?• Experimental research allows the researcher to control the

situations.

• Permits the researcher to identify cause and effect relationships

between variables and to distinguish placebo effects from

treatment effects.

• Experimental research designs support the ability to limit

alternative explanations and to infer direct causal relationships in

the study.

• Approach provides the highest level of evidence for single studies.504/10/23

What these studies don't tell you?• The design is artificial, and results may not generalize well to

the real world.

• The artificial settings of experiments may alter subject

behaviors or responses.

• Experimental designs can be costly if special equipment or

facilities are needed.

• Some research problems cannot be studied using an

experiment because of ethical or technical reasons.

• Difficult to apply ethnographic and other qualitative methods

to experimental designed research studies. 604/10/23

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BASIC TERMINOLOGIESBASIC TERMINOLOGIES

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Before & after without Control Design

After Only with Control Design

Before & After with Control Design

Completely Randomized Design

Randomized Block Design

Latin Square Cross Over Design

Factorial Design

TYPES OF EXPERIMENTAL DESIGNSTYPES OF EXPERIMENTAL DESIGNS

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BEFORE & AFTER WITH CONTROL DESIGN

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• In this designs two areas are selected & the dependent variable is measured in both for identical time period before the treatment.

• The treatment is then introduced into the test area only & the dependent variable is measured in both for identical time period after the introduction of the treatment.

• The treatment effect is determined by subtracting the change in dependent variable in control area from the change in dependent variable in test area.

TIME PERIOD I TIME PERIOD II

TEST AREA LEVEL OF PHENOMENON BEFORE TREATMENT (X) TREAT.INTRODUCED

LEVEL OF PHENOMENON AFTER TREATMENT (Y)

CONTROL AREA LEVEL OF PHENOMENON WITHOUT TREATMENT (A)

Treat effect=(Y-X)-(Z-A) LEVEL OF PHENOMENON WITHOUT TREATMENT (Z)

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AFTER ONLY WITH CONTROL DESIGN

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• One of the forms of experimental design used in marketing research.

• Here the researcher manipulates the independent variable and then it is followed by a post measurement.

• Two groups are post measured, that is, control and experimental groups.

• The difference between the groups is mainly attributed to be the affect of independent variable.

• This design escapes the problems of pretesting, history and maturation. However, this form of "after-only design" does not facilitate an analysis of the process of change.

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COMPLETELY RANDOMIZED DESIGN

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• In a completely randomized design, objects or subjects are

assigned to groups completely at random.

• One standard method for assigning subjects to treatment

groups is to label each subject, then use a table of random

numbers to select from the labeled subjects.

• This may also be accomplished using a computer.

• One of the most widely used experimental designs.

• The design is especially suited for field experiments where

the number of treatments is not large.

• The primary feature is the presence of blocks of equal size,

each of which contains all treatments.04/10/23

ADVANTAGES:

1. The design is extremely easy to construct.

2. The design is easy to analyze even though the sample sizes might not be the same for each treatment.

3. The design can be used for any number of treatments.

DISADVANTAGES:

1. Although the completely randomized design can be used for any number

of treatments, it is best suited for situations in which there are relatively

few treatments.

2. The experimental units to which treatments are applied must be as

homogeneous as possible. Any extraneous sources of variability will tend

to inflate the error term, making it more difficult to detect differences

among the treatment means.1204/10/23

RANDOMIZED BLOCK DESIGN

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• If an experimenter is aware of specific differences among groups of subjects or objects within an experimental group, he or she may prefer a randomized block design to a completely randomized design.

• In a block design, experimental subjects are first divided into homogeneous blocks before they are randomly assigned to a treatment group.

• If, for instance, an experimenter had reason to believe that age might be a significant factor in the effect of a given medication, he might choose to first divide the experimental subjects into age groups, such as under 30 years old, 30-60 years old, and over 60 years old.

• Then, within each age level, individuals would be assigned to treatment groups using a completely randomized design.

• In a block design, both control and randomization are considered.

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ADVANTAGES:

1. The design is useful for comparing t treatment means in the presence of a single extraneous source of variability.

2. The statistical analysis is simple.

3. The design is easy to construct.

4. It can be used to accommodate any number of treatments in any number of blocks.

DISADVANTAGES:

1. Because the experimental units within a block must be homogeneous, the design is best suited for a relatively small number of treatments.

2. This design controls for only one extraneous source of variability (due to blocks). Additional extraneous sources of variability tend to increase the error term, making it more difficult to detect treatment differences.

3. The effect of each treatment on the response must be approximately the same from block to block.

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LATIN SQUARE CROSS OVER DESIGN

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• Latin square design contains t rows and t columns.

• The t treatments are randomly assigned to experimental units within the

rows and columns so that each treatment appears in every row and in

every column.

• Each formulation is administered just once to each subject & once in each

study period.

• Unlike parallel designs, all the subjects do not receive the same

formulation at the same time, in a given study period , they are

administered different formulations.

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ADVANTAGES:

1. The design is particularly appropriate for comparing t treatment means in the presence of two sources of extraneous variation.

2. The analysis is quite simple.

DISADVANTAGES:

1. Although a Latin square can be constructed for any value of t, it is best suited for comparing t treatments.

2. Any additional extraneous sources of variability tend to inflate the error term, making it more difficult to detect differences among the treatment means.

3. The effect of each treatment on the response must be approximately the same across rows and columns.

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FACTORIAL DESIGN

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• In an experiment, independent variable is often called as factor, especially

in experiments that includes two or more independent variable.

• A research that includes two or more factors is called as factorial design.

• This kind of design is often referred to by the no. of its factors as a two

factor designs or three factor design.

• A research study with only one independent variable is often called as

single factor design.

• Each factor is denoted by letter (A,B,C).

• Factorial designs are the notation system that identifies both the no of

factors & the no of values or levels that exist for each factor. TYPES OF FACTORIAL DESIGNS : 1.Simple Factorial Design 2.Complex Factorial Design04/10/23

CONCLUSIONCONCLUSION• Experimentation offers the possibility of establishing a cause and effective

relationship between variables and this makes it an attractive methodology to researchers.

• Experiments are of two types: those conducted in a laboratory setting and those which are executed in natural settings; these are referred to as field experiments.

• Laboratory experiments give the researcher direct control over most of the variables that could affect the outcome of the experiment.

• There are a number of potential impediments to obtaining valid results from experiments.

• These may be categorized according to whether a given factor has internal validity, external validity, or both.

• Internal validity is called into question when there is doubt that the experimental treatment is actually responsible for changes in the value of the dependent variable.

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BIBLIOGRAPHYBIBLIOGRAPHY

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Thank You…..

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Thank You…..

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