If a categorical variable is to be included in a multiple regression,a dummy variable for each category of the variable should be used,but the original categorical variables should not be used.

Question

Quizplus · Accepted Answer

Including the original categorical variable in its raw form in a regression model is not appropriate because regression models require numerical input. Dummy variables (also known as indicator variables) are used to convert categories into a form that can be provided to a regression model, allowing the model to incorporate the effect of categorical variables by including one less than the total number of categories to avoid the dummy variable trap.

If a Categorical Variable Is to Be Included in a Multiple