1. Experimental Clinical Psychology Session VI
Eiko Fried
Department of Clinical Psychology
Leiden University

2. Exam Paper: today 3pm Be concise or you might not finish in time
Participation grades: soon!

4. AB & ABM What is AB What is ABM What are issues surrounding AB & ABM?
When reading the paper, do we have to take into account the year it was published in?

5. Q1
Read the Methods section of the paper by Schoorl et al. (2013). Describe the ABM (Attentional Bias Modification) procedure used in this study and its hypothesized working mechanism.

6. Q2
The control condition in this study is very different from common control conditions, such as a waiting list or treatment as usual (TAU). A) Briefly explain the control procedure used in this study. B) Which two threats to construct validity do the experimenters aim to control for by using this specific control condition? Briefly explain.

7. Q2b Experimenter Expectancies
Controlled for by RCT design, randomization
Single operations / narrow stimulus sampling
Kazdin 1: RCT, 1 therapist
Kazdin 2: stimulus material in 2 group is 1 specific person
Kazdin 3: Compare therapy X (therapists x1-x5) with Y (y1-y5)
Attention & contact accorded the client
Demand characteristics

8. Q2c
C) What is the downside of using this specific control condition, compared to a waitlist control group? Briefly explain.
Control group may be active
Control group may increase bias to threats

9. Q3
“The mean DPT score in both groups before treatment was close to 0 with a large standard deviation.” (Schoorl et al 2013, p. 103) This means that the patients in this trial on average did not show attentional bias to threat at the beginning of the study.
A) Give two possible explanations for this.
B) Is this (the absence of attentional bias at baseline) a problem for the interpretation of the results of the study? Briefly explain

10. Q3a

11. Q3b
“The mean DPT score in both groups before treatment was close to 0 with a large standard deviation.” (Schoorl et al 2013, p. 103) This means that the patients in this trial on average did not show attentional bias to threat at the beginning of the study.
B) Is this (the absence of attentional bias at baseline) a problem for the interpretation of the results of the study? Briefly explain.

12. Q4
As Kazdin explains in chapter 15, null-findings (or “negative findings”) can be very informative; for development of theory or treatment, but also for methodological improvement, if we have a clue about what is responsible for the null-finding. So a first step in deciding how to deal with a null finding is to identify the likely responsible factors. On page 379, table 15.1, Kazdin lists five obvious reasons for null-findings which have different consequences for interpretation and further research. For each of the categories 1, 2, 3 and 5 from Kazdin’s table 15.1, explain one potential reason for the null-finding in this study. Creativity and thinking beyond the obvious is encouraged, but your answer should be plausible and clearly explained.

13. Q4
As Kazdin explains in chapter 15, null-findings (or “negative findings”) can be very informative; for development of theory or treatment, but also for methodological improvement, if we have a clue about what is responsible for the null-finding. So a first step in deciding how to deal with a null finding is to identify the likely responsible factors. On page 379, table 15.1, Kazdin lists five obvious reasons for null-findings which have different consequences for interpretation and further research. For each of the categories 1, 2, 3 and 5 from Kazdin’s table 15.1, explain one potential reason for the null-finding in this study. Creativity and thinking beyond the obvious is encouraged, but your answer should be plausible and clearly explained.

14. Q4 Small difference in population
Manipulation inadequate / uncontrolled
Levels of independent variable
Too much error variability

15. Q4.2 The “crying baby” hypothesis

16. Additional questions
Based on the issues with ABM, and other reasons (from chapter 15, and ideas that you may come up with yourself), what do you think should be the next move for the research community with respect to ABM as a treatment (for PTSD)?

17. Evidence?

19. Overall stats Mean % correct from assignments: 84.3% 81.8% 84.7% 76.1%
83.8%
Overall: 83.6%

20. Course evaluation
What is the most important insight you have obtained/thing you have learned during this course?
Name one strength and one weakness of this course?
What should we improve next year?

21. Summary of the course Not all science is great Not all science is bad
Usually, it’s a bit of both

23. Break