ABSTRACT
You should now have a firm grasp on how to analyze continuous variables using multiple regression, along with a new appreciation of how to analyze categorical variables in MR. In this chapter we will combine these two types of variables to analyze both categorical and continuous variables in a single MR. Our discussion starts with the straightforward analysis of both types of variables in a single multiple regression. We then turn to focus on the addition of interactions to such analyses. Specific types of interactions between continuous and categorical variables are often of particular interest to psychologists and other social science researchers: aptitude-treatment interactions and bias in the predictive validity of tests. We cover examples of such analyses. In the next chapter we will expand our
discussion of interactions to cover interactions of two continuous variables and the analysis of potential curvilinear effects.
