A two-valued qualitative variable can be represented by a single 0-or-1-valued "dummy" variable. If a qualitative variable has three or more possible values (e.g., make-of-car, or marital-status), ...

A "Seasonal Dummies" predictor is a special feature that adds to the model seasonal indicator or "dummy" variables to serve as regressors for seasonal effects. A Seasonal Dummies input is added to the ...

At times it is desirable to have independent variables in the model that are qualitative rather than quantitative. This is easily handled in a regression framework. Regression uses qualitative ...