Can I run multiple regression with mostly categorical independent variables? I'd appreciate some examples to cite this approach as one of my reviewers is insisting that I justify the use of multiple regression for categorical IVs.
2 DVs (test scores) interval
IVs -
1 score (1-5 scale)
Gender dummy coded
Age dummy coded 3 levels
Member of ethnic minority dummy coded
Time spent out of country dummy coded 4 levels
Academic Discipline dummy coded 4 levels
Since the independent variables are mixed (mostly categorical) is multiple regression still acceptable? I want to explore the relationship of the IVs independently and in combinations on the test scores (DVs).
Best Answer
Can you? Sure. But it'll no doubt be less work to use ANOVA. Mathematically, ANOVA is equivalent to regression; they're versions of the same general linear model. The mechanics vary depending on the software you're using, but ordering up an interaction (to show effects associated with combinations of predictors) is simpler if you use, e.g., Age*Academic Discipline in ANOVA than if you have to account for the many dummy variables you've created for regression.