1. Experimental Studies Heppner et al. (2015) Chap20
Class 3
Experimental Studies
Heppner et al. (2015) Chap20

2. Psychology’s History of Being Mesmerized

3. Placebo Effect https://www.youtube.com/watch?v=HqGSeFOUsLI
In 2002, researchers at the Houston VA Medical Center and at Baylor College of Medicine found that a common type of knee surgery known as debridement to be no more beneficial than a placebo surgery. Throughout a two year follow-up, the 180 patients in the study were unaware whether they had received the "real" or placebo surgery. Patients who received actual surgical treatments did not report less pain or exhibit better functioning of their knees compared to the placebo group.

4. Experimental Between Group Designs
Post-Test Only Control
Pre-Test -- Post-Test Control
Solomon Four Group (combination of 1 and 2 above)
Factorial Design
more than one independent variable; interactions gender x treatment
Dependent Sample Design (Matching) 4

5. Experimental Between Group Designs
Post-Test Only Control
Pre-Test -- Post-Test Control
Solomon Four Group
Factorial Design (e.g., Treatment X Therapist)
Dependent Sample Design (Matching)
# of previous episodes and severity depression, gender, marital status 5

6. Between Group Design Factorial Design: More than one IV Experimental
AlI IVs are manipulated
Ex Post Facto:
All IVs are status variable (not manipulated)

7. Between Group Designs: Therapy Outcome
Treatment Package Strategy
Dismantling Strategy
Additive Strategy
Parametric Strategy
Comparative Outcome Strategy
Common Factors Control Group Design -- Placebo
Moderation Designs

8. Cultural Modifications PCIT- GANA
Assessment of culturally influenced concepts at intake and continuously to individualize treatment
Framed program as educational/skill-bdng, vs therapy
Parent Child Interaction Therapy to
GANA Guiando Ninos Activos
Engagement protocol for fathers and extended family
Orientation/preparation for treatment – manage expectations
Increased attention to rapport building – longer sessions
Eliciting feedback – complaints “simpatia” script
Translation and simplification of handouts- represent Hispanics in pictures

10. Types Between Group Designs
Treatment Package Strategy
Dismantling Strategy
Additive Strategy
Parametric Strategy (structural components)

11. Types Between Group Designs
Treatment Package Strategy
Compared PCIT – GANA - TAU
Dismantling Strategy
Additive Strategy
Parametric Strategy (structural components)

12. Types Between Group Designs
Treatment Package Strategy
Compared PCIT – GANA - TAU
Dismantling Strategy
components of the same treatment
Additive Strategy
Parametric Strategy (structural components)

13. Types Between Group Designs
Treatment Package Strategy
Compared PCIT – GANA - TAU
Dismantling Strategy
components of the same treatment
Additive Strategy
Added new components (e.g. cultural evaluation: engagement protocol)
Parametric Strategy (structural components)

14. Types Between Group Designs
Treatment Package Strategy
Compared PCIT – GANA - TAU
Dismantling Strategy
components of the same treatment
Additive Strategy
Added new components (e.g. cultural evaluation: engagement protocol)
Parametric Strategy (structural components) (e.g. longer sessions for rapport bdng.)

15. Types Between Group Designs
Comparative Outcome Strategy
Common Factors Control Group Design -- Placebo
Moderation Designs
Client /therapist characteristics

16. Types Between Group Designs
Comparative Outcome Strategy
Common Factors Control Group Design -- Placebo
Moderation Designs
Client /therapist characteristics

17. Types Between Group Designs
Comparative Outcome Strategy
Compared PCIT- GANA-TAU
Common Factors Control Group Design -- Placebo
Moderation Designs
Client /therapist characteristics

18. Types Between Group Designs
Treatment Package Strategy
Dismantling Strategy
Additive Strategy
Parametric Strategy
Comparative Outcome Strategy
Common Factors Control Group Design -- Placebo
Moderation Designs

19. Dismantling vs. Package Strategies
Identify change mechanisms
Do specific ingredients work as expected?
VS.
How well the treatment works

20. Dismantling Strategy: How Treatment Effects Change
Effectiveness of (Jacobson et al. 1996):
BA BA + AT BA + AT + CT
Component Measure Ttreat. Group
Behavioral activation – Pleasant Event SCd BA
Coping skills AT (Dist Thinking) AT
Core schemas Exp Attrb Style CT
Change from pre-to post- treatment in depression and in each change mechanism

21. Which group to use in outcome analyses ?
# Sessions
Intent-to treat
Total sample
n = 58 (pre-test)
Partial completers
5+ Sessions
n = 44
Completers
Full treatment
n = %
Post-treatment
assessment
n = %

22. Table 2 Self Report Measures

23. Cohen’s d – effect size 0.2 small 0.5 medium 0.8 large
If two groups' means don't differ by 0.2 standard deviations or more, the difference is trivial, even if it is statistically significant.

24. Table 3 – Observational Measures

25. Significance Statistically Significant Findings
Clinically Significant Findings

26. Significance Statistically Significant Findings
Clinically Significant Findings
behavior problems (ECBI) and externalizing symptoms (CBCL)
GANA /PCIT-
below normative mean
TAU
below clinical mean

27. External and Internal Validity
E I
Experimental
Field
E i
Correlational/
Descriptive
e I
Laboratory
e i

28. External and Internal Validity
E I
Experimental
Field
E i
Correlational/
Descriptive
e I
Laboratory
e i
Clinical Trials