Hello All

I need help to model a Moderated Mediation problem. My X (IV), Y (DV) and Mediation Variable (M) are numeric and continuous. Moderator variable (W) is categorical with 4 categories and is used with IV.

I intend to use R package "mediation". I am able to run mediate function. I want to see the individual effects using test.modmed function. It has arguments for 2 covariates only. I have no clue about how to model multiple categories of modVar (W) in test.modmed . (In my case, W has 4 categories)

Can some one guide me about this function usage for a categorical variable with 4 categories? (Usage of SPSS is not an option)