Mediation vs Moderation Flashcards
When a variable acts as a moderator, what does this mean?
That the effect of the IV on the DV depends on the values of another variable
Does a moderator variable need to be categorical?
No, moderators, can be either categorical or continuous
According to Baron and Kenny, when is a moderator variable usually introduced?
When there is a weak or inconsistent relationship
Is the relationship between the moderator variable on the IV and DV always linear?
No, a moderator relationship can be linear, non-linear and stepped
Is the following regression equation, which is the moderating variable: Y = c + d1x + d2z + d3xz + error
d3xz
Moderation tests a causal pathway?
No, moderation does not test a causal pathway
The equation for Moderation
Y = a + b1x + b2z + b3xz
A moderator variable is another word for:
Interaction variable
What is centering?
When every case for a variable is subtracted from a common value, usually the mean of the variable
While there is debate about centering variables, when examining interactions what is one of the arguments for centering interaction variables?
Reduces problems associated with multicollinearity
Does the method of interpreting the interaction change if other control variables are introduced into the regression model?
The interaction term is interpreted in the same way, however the beta coefficient may change
What is meant when we use the term non-additivity?
That for different values of independent variables the relationship with the dependent variable and the moderator may differ?
What is an effective way of trying to understand the non-addivity relationship of an interaction variable?
Plotting values of the interaction variable
What utility can be used with SPSS to help plot interactions?
Process utility
A plot of simple slopes with a significant interaction should have lines that are:
Slopes that are not parallel
A mediation analyses is examining what?
A causal pathway, and whether there is and intervening variable between the IV and DV
If using regression Baron and Kenny suggest how many regression models should be run:
Three: This tests the total effect, direct and indirect effect
Using the Baron and Kenny approach, and the figures here, when is full mediation identified?
When c` is not significant and c was originally significant
Using the Baron and Kenny approach, and the figures here, when is partial mediation identified?
When c` is reduced in magnitude compared to c
Using the Baron and Kenny approach, and the figures here, when is no mediation?
When b is not significant
What statistical program is used to test for mediation?
Mplus
Must mediation analyses be done with only continuous variables?
No, the IV, MV and DV can be either binary or continuous
When using SPSS to run a mediation analyses, what three key output results are produced?
Total effect (c), direct effect (c`); and indirect effect (a*b)
Mediation can expressed in the following way:
total effect = direct effect + indirect effect
Mathematically, mediation can also be expressed in the following way:
c = c’ + (a*b)
Mediation effect sizes can be used to assess:
How much of the total effect is mediated
According to Fergusson (2009), a moderate to large effect size is greater than:
>=.25
Which of the following statements is correct?
- Factor analysis takes a small number of variables and combines into a large number of factors
- Confirmatory factor analysis allows us to test a proposed model about how variables relate to each other
- Whereas exploratory factor analysis uses dimensions/factors to explain shared variance among variables in the analysis, confirmatory factor analysis uses dimensions/factors to account for all variance (shared and unique) in the model
- Factor analysis suggests that two variables are related, but doesn’t propose a shared third-variable to explain this association
Confirmatory factor analysis allows us to test a proposed model about how variables relate to each other
