1. Steps in the Research Process
Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

2. Developmental Designs
Longitudinal designs
participants are tested at different ages in their lives.
a single sample of participants may be tested at age 5, 10, 15, and at age 20.
treat age as a within-subjects variable
Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

3. Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

4. Developmental Designs
Cross-sectional designs
developmental designs that treat age as a between-subjects variable
compare different age groups of participants
each participant contributes data for only one age group.
Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

5. The Nuts and Bolts of Other Specialized Designs
Chapter 13
The Nuts and Bolts of
Other Specialized Designs
Dawn M. McBride
The Process of Research in Psychology
Second Edition

6. Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

7. Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

8. Developmental Designs
A cohort-sequential design
Multiple samples of participants of different ages are followed over time
Begin as a cross-sectional design: with separate samples of different age groups
The age groups are tested multiple times as they develop as in a longitudinal design.

9. Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

10. Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

11. Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

12. Developmental Designs
Longitudinal design
age -- within-subjects variable
testing effects
mortality/attrition
Cross-sectional design
age -- between-subjects variable
Cohort-generation effects
Cohort Sequential design
combines longitudinal and cross-sectional
Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

13. Longitudinal sources of bias:
Testing effects
early testing may affect later testing
Mortality/attrition
participants who drop may be different from those who remain
Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

14. Cross-sectional sources of bias:
Cohort- Generation Effects
Different generational experiences may affect the way the participants complete the task or measure in the study
Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

15. Small n Designs
experiments conducted with one or a few participants to better understand specific behaviors
Discrete trials design
Baseline design
Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

16. Discrete Trials Designs
Within-subjects experiment
Designed to study basic “laws” of behavior
Ex. Few individuals carry out computer task over many trials to test behavior under different types of reinforcement conditions
Positive – gain $
Negative - prevent form loosing $
Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

17. Discrete Trials Designs: Skinner Box

18. Baseline Designs
Experiment or Quasi-experiment done on an individual or small group to examine effects of treatment on undesirable behavior
A-B-A/reversal design –
measure baseline behavior,
give treatment,
measure baseline again
Confound: carry –over effects
Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

19. Data Analysis in Small-n Designs
Example : compare approaches to increase task completion among brain injury patients
Assigned vs. self selected (Tasky et al, 2008)
Data are often presented separately for the individual participants in the study
Inferential statistics can only be used in baseline designs if a large number of observations is collected for each individual.
Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

20. Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

21. Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.

22. Dawn M. McBride - The Process of Research in Psychology, 2nd Edition © 2013 SAGE Publications, Inc.