Thursday, February 9, 2017

Improving intuitions about mediation models

As part of preparing a revision for this project, I have done a lot of reading and thinking about statistical mediation models.  These models are often used when you wish to find the reason a manipulation exerts its impact on another variable -- the mechanism for the effect.

As I have described elsewhere, let's say you have predictor variable $X$, outcome $Y$, and a variable $M$ that you think transmits the impact of $X$ on $Y$.  You can think of this situation in terms of the following diagram: