Class 3 Between Group Designs, Expo Facto Designs, Status Variable

1. Class 3Between Group Designs, Expo Facto Designs, Status Variable Chapters HWK 7 (146-183),10 (224-233, 243-4) 12(308) ANOVA PDF

2. Between Group Design

3. Between Group Design

4. Within Group Design

5. Advantages of Pre-Test • Select participants; describe groups • Use as a covariateto control for differences in the groups before treatment • Compare outcome among drop-outs and completers • Use as post-test for early terminatorsin “intent to treat” analyses

6. Treatment Study: Question 5 • Research Design • Independent Variables • Dependent Variables • Participants

7. Treatment Study: Question 5 • Research Design • Experimental, BW-groups, posttest, factorial • Independent Variables • Treatments: Cult. Infused vs. Standard • Therapist Ethnicity: Latino/a vs. White • Dependent Variable(s) • Scores Parenting Skills - Continuous • Participants • 100 Moms of Mexican descent

8. Research Questions • Main Effect 1 • Main Effect 2 • Moderation: Moderator-- ??

9. Analysis: Study Question 5

10. Factorial Design: ANOVA • Examine the independent and interactiveeffect(association) of two or more independent variables on a dependent variable • IV – True Independent V. vs. Status Variables • ANOVA ---- ANCOVA

11. 2X2 ANOVA with ModerationDV- Post-Test Parenting Scale

12. Research Questions Study Question #5 • Main Effect Treatment: Does the culturally infused treatment yield a higher mean score in mom’s post-test parenting skills ratings than the treatment as usual? • Main Effect Therapist: Do Latino/a therapists yield a higher mean score in mom’s post-test parenting skills ratings than Anglo therapists?

13. Research Questions Study Question #5 • Interaction Effect: Moderator: Therapists’ Ethnicity

14. 2X2 ANOVA with ModerationDV- Post-Test Parenting Scale

15. 2X2 ANOVA with ModerationDV- Post-Test Parenting Scale

16. Table 1 Main Effects Means Post-Test Parenting Scale

17. Research Questions Study Question #5 Results Main Effect Treatment • Main Effect Treatment: Does the culturally infused treatment yield a higher mean score in mom’s post-test parenting skills ratings than the treatment as usual? Moms in the culturally infused treatment obtained a higher mean score in the parenting skills scale (4.1) than moms in the treatment as usual (2.9).

18. Research Questions Study Question #5 Results Main Effect Therapist • Main Effect Therapist: Do Latino\a therapists yield a higher mean score in mom’s post-test parenting skills ratings than Anglo therapists? Moms with Latino/s therapists did not obtain a higher mean score in the parenting skills scale (4.1) than moms with Anglo therapists (2.9).

19. Table 2B Does Therapist ethnicity moderate the effect of treatment type to parenting skills?

20. Research Questions Interaction Effects Study Question #5 • DoesTherapist ethnicity moderate the effect of treatment type to parenting skills? • Does the culturally infused vs. the usual treatment produce a higher mean score in mom’s post-test parenting skills ratings when administered by the Anglo Therapists? • Does the culturally infused vs. the usual treatment produce a higher mean score in mom’s post-test parenting skills ratings when administered by the Latino/a Therapists?

21. Table 2B Does Therapist ethnicity moderate the effect of treatment type to parenting skills?

22. Does Therapist Ethnicity moderate the treatment difference in parental skills? ?? • Does the culturally infused vs. the usual treatment produce a higher mean score in mom’s post-test parenting skills ratings when administered by the Anglo Therapists? Yes - 4.2 vs. 2.9 *p <.05 • Does the culturally infused vs. the usual treatment produce a higher mean score in mom’s post-test parenting skills ratings when administered by the Hispanic TherapistsYes – 4.3 vs. 3.3 *p <.05

23. Does Therapist Ethnicity moderate the treatment difference in parental skills? NO Therapists’ ethnicity did not matter: with both types of therapists, mothers in culturally infused treatment obtained higher post-test parental skills scores than mothers in usual treatment.

24. Summary of Findings • Main Effects: Treatment: Therapist Ethnicity • Moms in the Culturally Infused treatment (combining therapists) obtained higher scores in the post-test measure of parenting skills than moms in the Usual treatment. • Moms who received treatment from Latino/a therapists (combining treatments) obtained similar scores in the post-test measure of parenting skills than moms who received treatment from Anglo therapists.

25. Summary of Findings: Interaction Effects: Ethnicity as moderator of treatment type differences • Regardless of therapists’ ethnicity, moms in the culturally infused treatment obtained higher post-test parenting skills scores than moms in the treatment as usual. • Therefore, therapist ethnicity did not moderate the effect of type of treatment to outcome: mothers’ level of parental skills scores.

26. Conclusion • If interaction effect(s) is present, related main effect(s) is (are) not interpreted. • In this case, should we interpret the treatment main effect?

27. Table 3 2X2 ANCOVA with Moderation DV: Post-Test Parenting ScaleCovariate: Pre-Test Parenting Scale

28. Second Study Question 6 • Independent Variables • Dependent Variables • Participants

29. Second Study Q. 6

30. Research Questions Study Question # 6 • Main Effect Place of birth: Do moms born in USA obtain higher scores in pre-test parenting skills than moms born in Mexico? • Main Effect Child’s Gender: Do moms of boys obtain higher scores in pre-test parenting skills than moms of girls? • Interaction Effect: Moderator??

31. Main Effects • Place of Birth: • It is hypothesized that: • Child’s Gender • It is hypothesized that:

32. Main Effects • Place of Birth: • It is hypothesized that mothers born in the US will obtain higher scores in parenting skills than mothers born in Mexico • Child’s Gender • It is hypothesized that mothers of boys will obtain higher scores in parenting skills than mothers of girls

33. Table 4: 2X2 ANOVA Main EffectDV- SR Parenting Scale #6

34. Table 4: 2X2 ANOVA Main EffectDV- SR Parenting Scale #6

35. Moderation Effect • Mother’s Place of Birth will moderate the association of child’s gender to pre-test parenting skills so that: • Among mother’s born in US • Among mother’s born in Mexico

36. Moderation Effect • Mother’s Place of Birth will moderate the association of child’s gender to pre-test parenting skills so that: • Among Mothers born in US, there will be no difference in parenting skills among mothers of boys compared to mothers of girls • Among mothers born in Mexico, mothers of boys will obtain higher scores in parenting skills than mothers of girls

37. Table 4: 2X2 ANOVA with ModerationDV- SR Parenting Scale #6

38. Table 1 Parenting Skills Main Effect: Mom’s Country of Birth and Child’s Gender

39. Result Main Effects: Place of Birth Question #6 Table 5 • Do moms born in USA obtain higher scores in parenting skills than moms born in Mexico? • Answer: No 2.8 vs. 2.9 NS

40. Results Main Effects: Child’s Gender Question #6 Table 5 • Do moms of boys obtain higher scores in parenting skills than moms of girls? • Answer: Yes, 3.3 vs. 2.3 p<.05

41. Research Question Interaction Effects Study Q. #6: Mom’s Place Birth Moderator • Does mom’s place of birth make a difference in the association of child’s gender to mom’s parenting skills: • Among Moms born in Mexico, do moms of boys obtain higher scores in parenting skills than moms of girls? • Among Moms born in USA, do moms of boys obtain higher scores in parenting skills than moms of girls?

42. Table 2 Means Parenting Skills Ratings by Child’s Gender within Mom’s Country of Birth

43. Research Question Interaction Effects Study Q. #6: Mom’s Place Birth Moderator • Does mom’s place of birth make a difference in the association of child’s gender to parenting skills: Yes • Among Moms born in Mexico, moms of boys obtained higher scores in parenting skills than moms of girls? 3.8* vs. 1.9 p<.05 • Among Moms born in USA, moms of boys obtained similar scores in parenting skills than moms of girls? 3.1 vs. 2.5 NS

44. Conclusions • Only among Mom’s born in Mexico, moms of boys scored higher in the parenting skills questionnaire than mom’s of girls. • Therefore, the main effect for child’s gender applies only to mom’s born in Mexico. • Suggests that validity of parenting skills questionnaire may be related to mom’s acculturation to US- question for further research.

45. Comparison of Studies

46. Differences in Studies Questions #5 and #6 (1/2) • Nature of IVs and DVs • # 5 Both Vs are manipulated #6 Both IVs are inherent to participants • #5 & #6 IVs are categorical • #5 & #6 DVs are continuous • Design • #5 Experimental factorial • #6 Expo-facto factorial

47. Differences Studies in Questions #5 and #6 (2/2) • Assignment of participants to conditions, • #5 random • #6 characteristic inherent to participants • Statistical analyses • Both: ANOVA with interaction effects • Inferences from results • #5 Causal vs. #6 Association

48. Survey or Expo- Facto • What is the incidence of PTSD among veterans from the IRAQ war: total, by gender and by ethnic group. • Is there an association between gender and ethnicity (B H W) and PTSD in veterans from the IRAQ war. • Should we expect gender and ethnic differences; why?