We can use continuous variables, such as psychological test scores, qualitative variables, such as occupational type, or dichotomous variables such as voter/non-voter, male/female.

Data - values of qualitative or quantitative variables, belonging to a set of items.

A complicating factor is that the large number of different variables which describe the product, the store and the promotion attributes, both quantitative and qualitative, could potentially have many different values.

In regression analysis, the dependent variables may be influenced not only by quantitative variables (income, output, prices, etc.), but also by qualitative variables (gender, religion, geographic region, etc.).

For example, suppose Gender is one of the qualitative variables relevant to a regression.

In this model, a single dummy is assigned to each qualitative variable, one less than the number of categories included in each.

For example,in a regression involving determination of wages, if two qualitative variables are considered, namely, gender and marital status, there could be an interaction between marital status and gender.

Estimating at least seven measures for qualitative variables using randomized response sampling.

Statistical analysis Continuous variables are presented as mean one standard deviation while qualitative variables are presented as absolute and relative frequencies.

It is impossible to calculate outcomes with any certainty in a decision situation that involves qualitative variables.