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), ...

When some variables are quantitative and some qualitative in a response-surface context, standard designs may not be suitable. The reasons for this are illuminated. Some alternative designs are ...

Business owners are constantly gathering information to help develop strategies to improve marketing and sales. Ultimately, the goal is to improve the bottom line, with better targeting of a company's ...

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 ...

Expertise from Forbes Councils members, operated under license. Opinions expressed are those of the author. A human craving for simplicity is hindering retail’s optimization of artificial intelligence ...

The standard linear regression model does not apply when the effect of one explanatory variable on the dependent variable depends on the value of another explanatory variable. In this case, the ...