1. Chapter 10 Common Experimental Research Designs
Introduction to Educational Research: A Critical Thinking Approach
Chapter 10
Common Experimental
Research Designs 10
Chapter 10

2. Research Design
Researchers are designers, much like architects, creating different types of designs in their blueprints
Experimental Research Designs
Intervention or treatment known as a manipulation
True experimental
Quasi-experimental
Single-subject

3. True Experimental Designs
Research using designs that incorporate one or more true independent variables (manipulation plus random assignment)
Strong for testing cause-and-effect relationships
Randomized posttest control group design
Randomized pretest-posttest control group design
Randomized matched control group design

4. Key Timeline Pre R T Post Pre R C Post R= Random assignment
T=Treatment
C = Control
Pre=Pre-test measurement
Post=Post-test measurement after the treatment i.e., the Results
Timeline
Shinn, 2008

5. What can we say about the results?
(Non-R) T Post
New reading program, Principal of Adams just arbitrarily named 10 students, had them participate, and gave a post-test.
What can we say about the results?
Shinn, 2008

6. What can we say about the results?
R T Post
New reading program, Principal of Adams, randomly selected 10 students, had them participate, and gave a post-test.
What can we say about the results?
Shinn, 2008

7. What can we say about the results?
R T Post
R C Post
New reading program, Principal of Adams, randomly selected and assigned 10 students to each group, had them participate, and gave a post-test.
What can we say about the results?
Shinn, 2008

8. What can we say about the results? Gain scores
R Pre T Post
R Pre C Post
New reading program, Principal of Adams, randomly selected and assigned 10 students to each group, administered a pre-test had them participate, and gave a post-test.
What can we say about the results?
Gain scores
Shinn, 2008

9. What can we say about the results?
(Pre) M R T Post
(Pre) M R C Post
New reading program, Principal of Adams, gives a pre-test to students. Using pre-test scores, matching pairs of students, random assignment to group. Each group similar composition with regard to the subject characteristic of the pre-test.
What can we say about the results?
Shinn, 2008

10. Pretest and Posttest

11. Randomized Factorial Designs
Interaction effect
Occurring in factorial designs when the influence of one factor depends on the level or category of a second factor (e.g., a treatment affects males but not females). Keyword is “depends”
Main effect
Occurring in factorial designs when the averages between categories of one factor overall are different (e.g., females averaged over treatment and control groups score differently than males averaged over treatment and control groups). Keyword is "overall"

12. Interactive Results of Spelling Test

13. Graph of Interaction

14. Noninteractive Results of Spelling Test

15. Graph Revealing No Interaction

16. Learning disabilities
Page 289 – Tournaki (2003)
Learning disabilities
Shinn, 2008

17. Tournaki (2003) Basic Hypothesis 100 Non-LD score LD D&P Strat
D&P
Strat
Shinn, 2008

18. Tournaki (2003) Basic Hypothesis 100 Non-LD 90 Score on accuracy 80 LD70 60 C
D&P
Strategy
Shinn, 2008

19. Quasi-Experimental Design
A research design that incorporates a quasi independent variable (an independent variable manipulation without random assignment)
Matched comparison group design
Time-series design
Counterbalanced Quasi-experiment

20. Possible Outcomes in a Time Series Quasi-experiment
Pre pre pre pre pre T post post post post post
Page 281
Shinn, 2008

21. Single-subject design
A type of quasi-experimental research design using one subject to test all treatment and control conditions over time
Baseline
(control)
baseline
treatment
treatment
Level of hyperactivity
What do you conclude? Confident? Defensible?
Shinn, 2008