Moderation and Mediation

Question 1

Moderator

Answer 1

A variable that affects the strength and/or direction of the relationship between a predictor and the outcome.

Question 2

Direct Effects

Answer 2

The direct effect of the IV on the DV. To assess, regress the DV on the IV.

Question 3

Additive Effects

Answer 3

The indirect effect of another variable on the DV. To assess, regress the DV on the other variable.

Question 4

Testing Moderation

Answer 4

Need to centre means then enter the centred predictor and moderator into block one and the interaction into block two.

Question 5

Centering Means

Answer 5

Aids interpretation of the interaction and reduces the multicollinearity between the predictor and moderator.
Actual score - mean scorefor predictor and moderator

Question 6

Mediator

Answer 6

A variable that accounts for the relationship between a predictor and an outcome.
A causes B which causes C.

Question 7

Baron and Kenny (1986)

Answer 7

Method for testing mediation

1. Regress DV on IV
2. Regress Mediator on IV
3. Regress DV on Mediator and IV

Question 8

Criteria for Baron and Kenny

Answer 8

Analysis 1 and 2 must be significant and the mediator in analysis 3 must be significant. Sobel’s test must also be significant.

Question 9

Sobel’s Test

Answer 9

A z-test that identifies whether the indirect effect of the predictor on the outcome via the mediator is significantly different from zero.

Question 10

Assumptions of Mediation

Answer 10

Mediation assumes that the mediator is free of error. This can lead to biased coefficients.
If multicollinearity is too high, the test power is reduced

Question 11

Issues with Baron and Kenny

Answer 11

Methods no longer used because they are outdated and flawed, but it does provide a good basis for understanding mediation and moderation.