Quantitative variables take the form of numerical figures. Qualitative variables describe data by placing them into broad categories. For example, the number of units that your business sells over a ...

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), ...

This paper proposes a method for analysing relations between a qualitative variable and a group of quantitative variables. The method is an extension of known results concerning the analysis of ...

This note describes some serious errors in the paper by H. M. Kritzer (1977). The topics considered touch upon differences between recursive and non-recursive systems of equations, the measurement of ...