49
| Date post: | 17-Aug-2014 |
| Category: |
Education |
| Upload: | dr-jayesh-patidar |
| View: | 606 times |
| Download: | 79 times |
2/18/2014 2www.drjayeshpatidar.blogspot.com
CLASSIFICATION OF RESEARCH DESIGN (POLIT & HUNGLER, 1999)
2/18/2014 3www.drjayeshpatidar.blogspot.com
ESSENTIAL CHARACTERISTICS OF EXPERIMENTAL DESIGNS
Randomization
Control Manipulation
Experimental Design
RANDOMIZATION
Participants being assigned to eitherreceive (experimental group) or notreceive (control group), thetreatment condition or intervention
(IV).
METHOD OF RANDOMIZATION
•Lottery method
•Tossing a coin
•Random number table
•Computer
MANIPULATION
Manipulation is the process of maneuvering the IV, so that its effect on the dependent variable (D.V) can be observed/measured.
METHOD OF MANIPULATION
Researcher gives intervention to experimental group and withholds it to the control group or administers some other treatment. E.g. Gentle message is effective as a pain relief measures for elderly.
CONTROL
Control is for elimination of bias.
Control group refers to a group of subjects, whose performance is used to evaluate the performance of experimental group on same D.V.
Eg. Effect of nutrient diet on the weight of premature infant in two weeks.
Comparison of post intervention weight with pre-intervention weight determines the effectiveness of nutrient diet.
CONTROL
The type of experimental design is determined by the amount of control the researcher is able to exercise over the research condition.
CONTROL
1. TRUE EXPERIMENTAL DESIGN
1.1 Classic experimental design/pretest-post test control group design
R O1 x O2 (Experimental group)
R O1 O2 (Control group)
Experimental
Group- E
Pre test Treatment (X) Post test (x)
Control group-
C
Pre test Post test (y)
Example
•Tepid sponge (IDV) --> reduction of temperature (DV)
•Paracetomol (IDV) --> reduction of temperature (DV)
COLLECT PRETEST DATA BEFORE RANDOMIZATION TWO GROUPS
Example of Pre test – Post test Design.
2/18/2014 13www.drjayeshpatidar.blogspot.com
Example of True Experimental Study
Sneha, “Effectiveness of massage on the selected physiological variables of low birth weight infants”. In NICU of BharatiHospital, Pune, 2010.
2/18/2014 14www.drjayeshpatidar.blogspot.com
1.2 Post test only control group design
R X O1 (Experimental group)
R O1 (Control group)
Experimental group E Intervention
introduced
X
Level of phenomenon
after intervention (Y)
Control group C Level of phenomenon
without intervention (Z)
Intervention Effect =(Y)-(Z)
Example of Post-Test only Control Group Design
2/18/2014 16www.drjayeshpatidar.blogspot.com
Example of Post Test only Control Group Design
Vijayakumari G: A study to assess the effectiveness of structured teaching program regarding nature and prevention of accidents among mothers of toddlers in selected areas of Raichur (2004).
2/18/2014 17www.drjayeshpatidar.blogspot.com
2. QUASI-EXPERIMENTAL DESIGNS
A quasi experimental design is one in which experimental and control (comparison) are present & randomization is not there.
Ex. Effect of primary Nursing education on staff morale.
2/18/2014 18www.drjayeshpatidar.blogspot.com
2.1 Non equivalent control group design
R O1 X O2
R O 3 O4
Effect = (O2 – O1) – (O4 – O3)
R = Randomization.
O = Observation or measurement
X = Treatment or intervention
A researcher might choose a group of patients with diabetes on one hospital floor for the experimental group and a group of patients with diabetes on another floor for the comparison group. The experimental treatment would be administered to the experimental group; the comparison group would receive no treatment or some alternative treatment.
E.g. A non-equivalent control group design was used by Valliammal Sudhakar (2008) to study the knowledge, attitude and practice towards physical well being of a group of IV, V, VIth grade students in two different schools.
2.2 THE TIME SERIES DESIGN
• The time series design, a single group experiment comprises of series of observation in the before-time period to establish a baseline.
• The experimental independent variable is then introduced,
• Followed by another series of observation to examine the effect of the independent variable.
2/18/2014 22www.drjayeshpatidar.blogspot.com
2.2.1 Time series Design (single group)
Before x After
………...……………………………………...E O1 O2 O3 O4 O5 x O6 O7 O8 O9 10
………………………………………………
2/18/2014 23www.drjayeshpatidar.blogspot.com
2.2.2 The Multiple Time Series DesignTime series non equivalent control group design
(QED)
Before x After
………………………………………………………..E O1 O2 O3 O4 O5 x O6 O7 O8 O9 10
………………………………………………………………………………………
C O1 O2 O3 O4 O5 - O6 O7 O8 O9 10
……………………………………………………………………………
2/18/2014 24www.drjayeshpatidar.blogspot.com
A researcher might assess the pain levels
of a group of patients with low back pain.
After 3 weeks of pain assessment, intervention will be introduced
(O1 O2 O3 x O4 O5 O6).
The results of this study would help the researcher to determine if a specific exercise
is effective in reducing low back pain.
3. PRE EXPERIMENTAL DESIGN
Pre experimental design: are discussed to provide examples of how not to do research.
PRE-EXPERIMENTAL DESIGNS:
3.1 The one-shot case study or single case study
In single case study, that studies at once, following a treatment or an agent presumed to cause change. Because the study design has a total absence of control; it is considered to be little value as an experiment
X----------------O
X= independent variables or stimulus
2/18/2014 27www.drjayeshpatidar.blogspot.com
ONE-SHOT CASE STUDY
Lalitha, Premila & Balu (2006) conducted a study on nursing personnel registered for a day workshop on life skill education at MTIHS, Pondicherry.
3.2 ONE GROUP PRE-TEST AND
POST-TEST DESIGN
• Here only one group is observed before and after the independent variable is introduced.
• Loss of the control group decreases the usefulness of the study but may be necessary in cases where it is not possible or feasible to have control groups
2/18/2014 29www.drjayeshpatidar.blogspot.com
E.g. Sailaxmi Gandhi(2006) conducted a pre-experimental study to assess the effectiveness of stress management programme on the selected variables of nurses working in psychiatric wards at NIMHANS, Bangalore.
II- NON EXPERIMENTAL DESIGN
Non-experimental
2/18/2014 32www.drjayeshpatidar.blogspot.com
2/18/2014 36www.drjayeshpatidar.blogspot.com
2/18/2014 38www.drjayeshpatidar.blogspot.com
CONCLUSION
• Quantitative research approach is the commonest
• Replication is possible
• Data analysis is easy
• Researcher’s subjectivity is minimal
2/18/2014 48www.drjayeshpatidar.blogspot.com
2/18/2014 49www.drjayeshpatidar.blogspot.com
