2. Types of Experimental Designs (Educational research) True Experimental Quasi-Experimental

3. Types of Experimental Designs Simple True Experimental Quasi-Experimental

4. Types Randomized posttest control group design Randomized pretest-posttest control group design

5. Randomized posttest control group design RTPost RCPost

6. Randomized pretest-posttest control group design RPreTPost RPreCPost Makes it possible to ascertain that groups were equivalent at the beginning of the study. Not necessary if: 1. Randomization was used 2. Large sample size

7. Solomon four-group design RPreTPost RPreCPost RTPost RCPost Four groups are formed by random assignment ( R ) of participants, two groups are pretested ( O ) and two are not, one pretested and one unpretested group receive the experimental treatments ( X1, X2 ), each group is administered a posttest on the dependent variable, and posttest scores are compared to determine effectiveness of treatments

8. Types of Experimental Designs Simple True Experimental Quasi-Experimental

9. Characteristics of True Designs Manipulation (treatment) Randomization Control group Less control More real-world Program evaluation

10. Quasi-experimental Designs One group posttest-only design One group pretest-posttest design Non-equivalent control group design Non-equivalent control group pretest- posttest design Time series

11. Quasi-experimental Designs One group posttest-only design One group pretest-posttest design Non-equivalent control group design Non-equivalent control group pretest- posttest design Time series

12. Randomized posttest control only design RTPost RCPost

13. One group posttest-only design (One shot study) TPost No control of IV threats Use?

14. Quasi-experimental Designs One shot study One group pretest-posttest design Non-equivalent control group design Non-equivalent control group pretest- posttest design Time series

15. Randomized pretest-posttest control group design RPreTPost RPreCPost

16. One group pretest-posttest design PreTPost History Maturation Testing Instrumentation Regression Use control group

17. Quasi-experimental Designs One shot study One group pretest-posttest design Non-equivalent control group design Non-equivalent control group pretest- posttest design Time series

18. Randomized posttest control group design RTPost RCPost

19. Non-equivalent control group design (Static group comparison design) TPost CPost Selection bias

20. Quasi-experimental Designs One shot study One group pretest-posttest design Non-equivalent control group design Non-equivalent control group pretest- posttest design Time series

21. Randomized pretest-posttest control group design RPreTPost RPreCPost

22. Non-equivalent control group pretest-posttest design PreTPost PreCPost Can check selection bias

23. Quasi-experimental Designs One shot study One group pretest-posttest design Non-equivalent control group design Non-equivalent control group pretest- posttest design Time series

24. Pre Pre Pre Pre T Post Post Post Post …a single group is pretested ( O ) repeatedly until pretest scores are stable, exposed to a treatment ( X ) and, then, is repeatedly posttested ( O )