Lecture 10- Mediation And Moderation Flashcards
Mediation occurs when
The relationship between a predictor and an outcome can be explained by their relationship to a third variable- the mediator
A mediation model can be used whenever a what is used
Linear model
Mediation can be used in what designs
Correlational and experimental
What is total effect
The simple relationship between predictor and outcome
What is an indirect effect
The effect of the predictor on the outcome through the mediator
What is a direct effect
The effect of the predictor on the outcome, adjusting for the mediator
The total effect is comprised of the
Indirect and Direct effect
How could we test predictor outcome in r
Multiple regression adjusted for our predictor
To run a mediation in r what function is used
sem()
If the confidence intervals for not contain 0 and if the p value is less than .05 then
There is a mediation effect
What’s partial mediation
The direct effect is reduced but still significant- there’s both indirect and direct effect of the predictor on the outcome
What is full mediation
Direct effect is reduced to non-significance and the effect of the predictor on the outcome goes entirely through the mediator
What is a moderator
A variable that affects the relationship between two others
In a linear model with multiple predictors, each of the effects (bs) are interpreted when
The other variables in the model are 0
In grand mean centring the ‘fixed point’ is
The overall mean of that measure
Centring can be done using which function
mutate() and mean()
To make interpretation easier what is done
Centre variables by transforming them into deviations around a fixed point
High-order effects refer to
Interactions
Lower-order effects refer to
Main effects
If there is moderation effects what are we no longer interested in
Lower-order effects
If interaction is significant then we have
A moderation effect
What techniques can be used to follow up a significant interaction effect
- Simple slopes analysis
- Johnson-Neymon interval
What needs to be worked out after a significant interaction effect
The coefficient for our predictor at different values of our moderator
What is simple slope analysis
Comparing the relationship between our predictor and our outcome at low, mean and high levels of our moderator using SDs
What does the Johnson-Neymon Interval do
Estimates the model of our predictor and outcome at lots of different values of our moderator
What are the key pieces of information to report for a moderation
- The main effects
- The interaction effect
- Analysis if moderation was found
