Nominal Measure

A nominal measure is part of taxonomy of measurement types for variables developed by psychologist Stanley Smith Stevens in 1946. Other types of measurement include ordinal, interval, and ratio. A nominal variable, sometimes referred to as a categorical variable, is characterized by an exhaustive and mutually exclusive set of categories. Each case in the population to be categorized using the nominal measure must fall into one and only one of the categories. Examples of the more commonly used nominal measures in survey research include gender, race, religious affiliation, and political party.

Unlike other types of measurement, the categories of a variable that is a nominal measure refer to discrete characteristics. No order of magnitude is implied when comparing one category to another. After the relevant attributes ...