What is a Nominal Scale? Definition and Example

At the beginning of data collection, researchers must first consider how they can capture the object being studied. The central challenge of empirical research is to find a meaningful form of quantification. With the nominal scale, fixed objects or characteristics can be assigned to simple categories, which makes later statistical analysis possible.

General Definition of the Nominal Scale

The nominal scale (engl. “nominal scale” or “categorical scale”) is the lowest scaling for measuring qualitative characteristics (gender, marital status, hair color). With it, you can determine whether a certain characteristic expression (male/female, single/married, blonde/brown) is present – or not. When measuring on a nominal scale, units of analysis are assigned to characteristic categories.

The nominal scale is suitable for classifying characteristic expressions, whereby each case can only fall into a single category. The individual categories must be mutually exclusive (e.g. either female or male).

The individual response options on a nominal scale are, in contrast to interval or ratio scales, not directly represented in numbers, which is why it is considered non-metric in science.

 

 

Typical Use of the Nominal Scale

In empirical studies, the nominal scale can be used, for example, to determine whether respondents have a university degree or how many women participated in a survey.

1. Example 1: Select your gender (Female, Male, Diverse)
2. Example 2: What is your marital status? (Single, Married, Divorced, Widowed)

 

When evaluating nominal data, each category is assigned a numerical value, e.g. single - 1, married - 2, divorced - 3, widowed - 4. The assignment only serves the easier naming of the categories. From nominal data, primarily the mode or the characteristic expression with the greatest frequency is calculated.