1. Research Design in Psychology
Possible sources of headache

2. What may go wrong in research
Conceptualization problems
Design problems
Measurement design (= operationalization) problems
Measurement implementation problems
Statistical problems
Interpretation problems

3. Concepts of Design: NOT to be confused with Measurement (PSYC410)
Reliability
Validity – internal
Validity – external

4. Potential design problems
The worst and the most problematic: IV does not vary
Other events/experiences may interfere  Between WHAT and WHAT
Selection of the sample and groups – representativeness / attrition / non- participation
Problems with extreme groups
Problems with measurement
The way you measure or the fact that you measure it

5. Example: No variability
Divorced parents
Stability of relationships

6. Example: solution Whether there is a parental divorce
Stability of relationships

7. Example: Instrumentation
Reflection on parental divorce and feelings of insecurity
Whether there is a parental divorce
Report of stability of relationships
Actual stability of relationships

8. Example: History IV
HISTORY DV

9. Example: History (other “IV’s”)
Whether there is a parental divorce
Stability of relationships
Experience with relationships throughout adolescence

10. Example: history (Maturation)
Whether there is a parental divorce
Stability of relationships
Ability to interpret parental discord and evaluate it in perspective

11. Example: History (Social and personal events)
Whether there is a parental divorce
Stability of relationships
Economic difficulties, residential moves, changes of school, changes of social relationships

12. Example: History that occurs prior to the IV (third variable)
Psychological well being of parents prior to divorce
Whether there is a parental divorce
Stability of relationships

13. Example: Sample (Biased selection of subjects)
Whether there is a parental divorce
Stability of relationships
[KU]

14. Example: (explanation)Biased selection of subjects
Family functioning
OSS Scores
Whether there is a parental divorce
Stability of relationships
[KU]

15. Example: Biased selection of subjects (regression towards the mean)
Whether there is a parental divorce
Stability of relationships
[Clinical Sample]