1. Non-true-experimental Designs, cont. PSY 231 Research Methods in Psychology

2. Announcements Journal Article Summary #2 (or research participation alternative) due in labs this week bring results from group projects to lab GAs will go over plans of analyses with you

3. today Chapter 12—The Correlational Research Strategy Chapter 13—The Descriptive Research Strategy Chapter 10—The Nonexperimental and Quasi- Experimental Strategies: Nonequivalent Group, Pre-Post, and Developmental Designs Chapter 14—Single-Subject Research Designs Chapter 15—Statistical Evaluation of Data

4. balance of the validities internal—extent to which a research study produces a single, unambiguous explanation for the relationships between two variables external—extent to which we can generalize the results of a research study to people, settings, times, measures, and characteristics other than those in that study balance depends on level of experimental control

5. threats to internal validity assignment bias history maturation instrumentation testing effects

6. nonexperimental research vs. quasi-experimental research nonexperimental—intended to demonstrate a relationship between variables but does not attempt to explain quasi-experimental—uses some rigor and control of true experiments but contains a flaw that prevents cause-effect remember—true experiments include a control group manipulation of independent variable(s) random assignment to groups

7. nonexperimental research vs. quasi-experimental research both use comparisons between groups or conditions both use nonmanipulated independent variables attempts to control internal validity threats nonexperimental—no quasi-experimental—yes

8. nonexperimental research vs. quasi-experimental research two types between-subjects designs nonequivalent groups within-subjects designs pre-post designs

9. nonequivalent groups designs posttest-only nonequivalent groups assignment bias, no control of time effects nonexperimental participants program measure participantsno program measure

10. example smoker participants training program measure smokersno training program measure

11. nonequivalent groups designs pretest-posttest nonequivalent control design assignment bias, some control of time effects quasi-experimental participantsmeasureprogrammeasure participantsmeasureno programmeasure

12. example no t.v. aggression aggression participantsmeasure t.v.measure t.v. aggression aggression participantsmeasure (no change)measure

13. pre-post designs one-group pretest-posttest design little control of time effects nonexperimental participantsmeasureprogrammeasure

14. example smoker participantsmeasureprogram measure

15. pre-post designs time-series design some control of time effects quasi-experimental measuremeasuremeasuremeasure program measuremeasuremeasuremeasure

16. example 1951195219531954 1955 1959195819571956

17. developmental designs nonmanipulated independent variable—age or time three types cross-sectional longitudinal sequential

18. cross-sectional design different participants, at different ages, studied at same time year of birth19881978196819581948 age at study2030405060 year of study2008

19. cross-sectional design advantages time efficient no long-term cooperation disadvantages no individual changes cohort effects year of birth 19881978196819581948 age at study2030405060 year of study2008

20. longitudinal design same participants, at different ages, studied at different times year of birth1988 age at study2030405060 year of study20082018202820382048

21. longitudinal design advantages no cohort effects assesses individual changes disadvantages time consuming long-term cooperation year of birth1988 age at study2030405060 year of study 20082018202820382048

22. sequential design different participants, at different ages, studied at different times 2030405060 20304050 age at study203040 2030 20 year of study20082018202820382048

23. single-subject designs originally used in behavior modification often seen in clinical and applied settings not used very often in traditional research

24. single-subject designs different from traditional designs usually conducted with one person or a small group much more flexible require continuous assessment

25. single-subject designs baseline observations—no treatment administered baseline phase—series of baseline observations treatment observations—treatment administered treatment phase—series of treatment observations

26. reversal design also called ABAB design behavior is observed during baseline phase (A) treatment phase (B) baseline phase (A) treatment phase (B)

27. reversal design A B A B

28. multiple baseline designs reversal designs may not work need to show treatment is effective across circumstances multiple baseline across subjects behaviors situations

30. single-subject designs advantages establish cause-effect between treatment and behavior integrate experimental research with clinical practice allows flexibility

31. single-subject designs disadvantages cause-effect established for only one person needs multiple observations no statistical control

32. feedback thinking about my 2 lectures… please write down 1 thing you liked please write down 1 thing that you didn’t like/need to improve turn it in on the table along with Rating Sheet #1