Definition: Categorical data

Categorical data is statistical data comprising of categorical (i.e., qualitative) variables that are converted into categories. Categorical variables take on values that are names or labels. The color of a ball (e.g., red, green, blue) or the breed of a dog (e.g., collie, shepherd, terrier) would be examples of categorical variables.

Categorical data represents data types that may be divided into groups. Examples of categorical data are race, sex, age group, and educational level. While the latter two variables may also be considered as a numerical manner by using exact values for age and highest grade completed, it is usually more informative to categorize such variables into a relatively small number of groups.