Moderators and Mediators

Question 1

Moderator

Answer 1

A moderator is a qualitative or quantitative variable that affects the direction and/or strength of the relation between an IV (or predictor) and a dependent or criterion variable.

Moderation refers to the situation where the direction and intensity of an effect of a predictor on a
criterion depends on the levels or settings of a third variable. In essence, moderators attenuate or
exacerbate the effect.

Question 2

Moderator in correlation analysis framework

Answer 2

a moderator is a third variable that affects the zero order correlation between two other variable.

Question 3

Moderation and ANOVA

Answer 3

a basic moderator effect can be represented as an interaction between a focal IV and a factor that specifies the appropriate conditions for its operation.

Question 4

How to test moderation

Answer 4

Variables entered into the regression equation in a stepwise and hierarchical fashion.

Control variables (if any were collected) are entered first into the equation.

In order to derive main effects of X on Y, regress X onto Y for this step
- Add the interaction terms (X x M) to the analysis. If there is a change in total variance explained from step 3 to step 4 this suggests total moderational impact, and r values for each interaction term shows the impact of the moderator for each relationship.

Question 5

Mediator

Answer 5

A variable is said to function as a mediator to the extent that it accounts for the relation between the predictor and the criterion (X and Y). Mediators explain how external physical events take on internal psychological significance.

Question 6

Tests for Mediator Check

Answer 6

For a variable to be considered a mediator, it must pass three tests (Baron and Kenny, 1986):
X correlates with Y
X correlates with M
M significant impact on Y when X controlled for: aka, Effect of X on Y when M controlled for is 0 for full mediation

Question 7

Steps for moderation

Answer 7

1) X ⟶ Y (without pulling out the mediator)
2) Check for X → mediator, and mediator → Y
3) The direct effect is then X → Y , pulling out the mediator
4) Sobel test
5) Bootstrapping test

Question 8

Mediated Moderation

Answer 8

Moderator variable moderates the relationship between both the dependent variable and the mediator as well as the mediator and the independent variable.

Question 9

Mediated Moderation Check

Answer 9

The effect of X on Mediator must depend on moderator and Mediation directly effects Y.

X directly affects mediator and the effect of mediator on Y depends on moderator

the value of the effect of moderator controlling for the effect of the mediator must be less than the effect of the moderator without controlling for the mediator.

Question 10

Moderated Mediation

Answer 10

Moderator could be a context

There is a relationship between X and Y which is not moderated by moderator.

The indirect effect between X and Y depends on the moderator.

The effect of the moderator on X must be signification OR the effect of the moderator on the mediator must be significant.

• If former, then the effect of the mediator, controlling for the interaction between mediator and moderator, must be significant
• If latter, then the effect of the moderator interacted with X, controlling for non-interaction effects, must the significant.