I'm planning on running a hierarchical multiple regression. In the first step, I would like to enter demographic characteristics, second step continuous predictor variables of interest, and third step interactions between the continuous predictor variables. However, the issue I've run into is that some of the demographic variables are more than two levels and either nominal (e.g., education level: less than BA, BA, graduate degree) or ordinal (e.g., age: 20-30, 31-40, 41-50, 51+). My dependent variable is continuous.
My question is: can I dummy code the nominal/ordinal variables and then run the multiple regression as I normally would? Or, would you recommend handling the data differently? I'm using SPSS, so I appreciate any help/input. Thanks!