chp 10: Moderation, mediation and multicategory predictors.

Question 1

What is moderation?

Answer 1

the combined effect of two plus predictor variables on an outcome.

Question 2

The statistical term for moderation is…

Answer 2

an interaction effect.

Question 3

How do you solve the problem of variables that cannot equal zero such as heartrate of gamers.

Answer 3

Grand mean centreing

Question 4

How do you do grand mean centreing

Answer 4

transform the variable into deviations around zero.

Question 5

What effect does grand mean centreing have on the highest order predictors?

Answer 5

No effect.

Question 6

Does grand mean centreing have an effect on the lowest order predictors?

Answer 6

Yes. It effects the b

Question 7

Two interpretations of predictors b’s with centreed variables.

Answer 7

effect of that predictor at mean value of the sample.

avaerage effect of the predictor across the range of scores.

Question 8

Procedure for follow up for an interaction effect to work out what the nature of the effect is.

Answer 8

simple slopes analysis

Question 9

What is simple slopes analysis?

Answer 9

Compare slopes: direction, significance and values

Does the relationship between predictor and outcome change at different levels of the moderator.

Question 10

What is mediation?

Answer 10

When the strength of the relationship between a predictor variable and outcome variable is changed by another predictor variable.
Relationship is explained by a third variable.

Question 11

How is mediation tested?

Answer 11

By assessing the size of the indirect effect and its confidence interval.

Question 12

If the mediation confidence interval includes zero assume…

Answer 12

A genuine mediation effect does not exist.

Question 13

When is dummy coding used?

Answer 13

With categorical variables that have more than two categories

Question 14

How do you dummy code a categorical variable?

Answer 14

Code the variable into more variables with values of zero and one.

Question 15

1982 method for testing for mediation effect.

Answer 15

Sobel test.

Question 16

What does sobels test do?

Answer 16

Estimates indirect effect of a variable on outcome variable and its significance.

Question 17

How to interpret a sobel test?

Answer 17

If significant the predictor significantly affects the outcome via the mediator.
Works well with large samples.

Question 18

A method better than sobels for assessing mediation effects?

Answer 18

Bootstrap method and calculate confidence interval for indirect effect.

Question 19

Moderation example

Answer 19

a lot of stress, + good social support, = fewer symptoms of depression, anxiety, fatigue…) than someone with low social support. Social support is the moderating variable.

Question 20

mediation example

Answer 20

pizza increases positive morale which increases amount of work done

Question 21

Moderator variables influence

Answer 21

Strength and direction of the relationship between two variables.

Question 22

Mediator variables explain…

Answer 22

The relationship between two variables. The independent variable influences the mediator variable influences which influences the dependent variable