Week 9 Mediation

How would you identify if you need to use a mediation?

Asking a ‘why’ or ‘how’ questions 

What is mediation?

The relationship between two variables occurs because of a third variable 

Direct effect also known as the C’ path

The association between the predictor and the outcome not explained by the mediator 

Indirect effect otherwise known as A path x B bath

the association between the predictor and the outcome occurring through the mediator  

For mediation the direct path…

does not need to be significant, only the indirect part really needs to be significant 

a Partial mediation is where…

both indirect and direct paths are significant 

Full mediation is where

only the indirect path is significant not the direct path. meaning the effect is likley entirely due to the mediator.

How do researchers typically interpret “partial mediation”?

The mediator accounts for only some of the covariance between two variables; there are probably other reasons for the link too

uses for mediation models:

• They give evidence of links between variables through other variables

• You can build detailed models adding more variables in a “chain” of mediation.

• They are one way to think about “why” or “how” questions with associations