What is characteristic of a nominal scale?

A nominal scale is used for categorizing data without any quantitative value or order. The defining characteristic of this scale is that it consists of distinct categories that do not have a natural hierarchy or ranking. Each category is just a label for a particular group, and while they can be used to classify data, they do not convey any information about the relationship or order among those groups.

For instance, consider a nominal scale used in a survey where respondents choose their favorite color—red, blue, or green. These colors are simply labels with no inherent order; none is more or less than another. This characteristic sets nominal scales apart from other types, such as ordinal scales, where items do have a ranking, or interval scales, where the difference between values is meaningful.

Hence, the defining quality of a nominal scale is the absence of a natural order among the categories. The other choices involve properties of different types of scales; for example, options focusing on ordering or intervals pertain to ordinal and interval scales, and the idea of measuring continuous variables relates to ratio or interval scales.