2. Common Applications of Regression

3. Mediating Models Candy Teaching Evals Happy

4. Mediating Relationships IV DV Mediator a b c

5. Mediating Relationships IV Mediator a 1. There is a relationship between the IV and the Mediator

6. Mediating Relationships DV Mediator b 2. There is a relationship between the Mediator and the DV

7. Mediating Relationships IV DV c 3. There is a relationship between the IV and DV

8. Mediating Relationships IV DV Mediator a b c 4. When both the IV and mediator are used to predict the DV the importance of path c is greatly reduced

9. Common Applications of Regression Moderating Models Does the relationship between the IV and DV change as a function of the level of a third variable Interaction

10. Example Girls risk behavior –Cigarettes, alcohol, pot, kissing Openness to experience Pubertal Development How might pubertal development moderate the relationship between openness and participation in risk behaviors? –Note: pubertal development is the variable you think moderates the relationship (mathematically this is irrelevant)

11. Example Data were collected from 20 girls Mother’s rating of openness Doctor’s rating of pubertal development One year later girls report of risk behaviors –Sum risk behavior

13. How do you examine an interaction? Multiply the two variables you think will interact with each other –Openness x puberty Should always center these variables BEFORE multiplying them –Reduces the relationship between them and the resulting interaction term

16. How do you examine an interaction? Conduct a regression with: Centered IV 1 (openness) Centered IV 2 (puberty) Interaction of these (open x puberty) Predicting outcome (Sum Risk)

18. Graphing a Moderating Variable

19. Using this information it is possible to predict what a girl’s risk behavior would for different levels of openness and puberty.

20. Graphing a Moderating Variable Using this information it is possible to predict what a girl’s risk behavior would for different levels of openness and puberty. For example -- Imagine 3 girls who have average development (i.e., cpuberty = 0). One girl’s openness is 1 sd below the mean (copen = -1.14) One girl’s opennes is at the mean (copen = 0) One girl’s openness is 1 sd above the mean (copen = 1.14)

21. pubertyOpeno*pPred Y 0-1.140 000 01.140

22. pubertyOpeno*pPred Y 0-1.1402.87 0003.15 01.1403.43

23. -1.14 0 1.14 pubertyOpeno*pPred Y 0-1.1402.87 0003.15 01.1403.43

24. pubertyOpeno*pPred Y 1.28-1.14-1.46 1.2800 1.141.46 0-1.1402.87 0003.15 01.1403.43 More Average When graphing out – make different “lines” for each level of the variable you conceptualized as moderating

25. pubertyOpeno*pPred Y 1.28-1.14-1.462.70 1.28003.36 1.281.141.464.02 0-1.1402.87 0003.15 01.1403.43 More Average When graphing out – make different “lines” for each level of the variable you conceptualized as moderating

26. -1.14 0 1.14 pubertyOpeno*pPred Y 1.28-1.14-1.462.70 1.28003.36 1.281.141.464.02

27. pubertyOpeno*pPred Y 1.28-1.14-1.462.70 1.28003.36 1.281.141.464.02 0-1.1402.87 0003.15 01.1403.43 -1.28-1.141.46 -1.2800 1.14-1.46 More Average Less When graphing out – make different “lines” for each level of the variable you conceptualized as moderating

28. pubertyOpeno*pPred Y 1.28-1.14-1.462.70 1.28003.36 1.281.141.464.02 0-1.1402.87 0003.15 01.1403.43 -1.28-1.141.463.09 -1.28002.94 -1.281.14-1.462.84 More Average Less When graphing out – make different “lines” for each level of the variable you conceptualized as moderating

29. -1.14 0 1.14 pubertyOpeno*pPred Y -1.28-1.141.463.09 -1.28002.94 -1.281.14-1.462.84

30. -1.14 0 1.14 More Dev. Average Dev. Less Dev.

31. Practice Based on past research you know that martial happiness is related unhealthy dieting habits in women. However, you think that women’s esteem might moderate this relationship –Specifically, you think a woman with high self esteem will not be affected as greatly by a poor marriage as a woman with low self-esteem

32. Practice Date were collected from 172 women Martial Quality (M = 0; SD = 1) Esteem (M = 0; SD = 1) Unhealthy Dieting (Range 0 - 19) Determine if esteem moderated the relationship between marital quality and unhealthy dieting

35. EstMarE*MPred Y 13.90 003.21 1 2.51 002.83 0002.53 0102.23 1 1.76 1001.85 1111.93 Low Mod High When graphing out – make different “lines” for each level of the variable you conceptualized as moderating

36. -1 0 1 High SE Average SE Low SE

38. Handout DV = Risk Behavior (0 – 4) IV = Child’s perception of monitoring IV = Objective measure of monitoring

39. Handout Practice 1) Draw a causal model using the standardized regression coefficients. 2) Determine if the overall model significantly predicts risk behavior. 3) Compute the semipartial correlation for each IV 4) Determine if the unstandardized regression weights are significant. 5) Discuss in a few sentences what is the overall “story” being told by these data