what is an ordinal variable

An ordinal variable is a type of categorical, statistical data where the variables have natural, ordered categories and the distances between the categories are not known. These data exist on an ordinal scale, which is one of four levels of measurement described by S. S. Stevens in 1946. The ordinal scale is distinguished from the nominal scale by having a ranking. It also differs from the interval scale and ratio scale by not having category widths that represent equal increments of the underlying attribute. Examples of ordinal data include socioeconomic status, military ranks, and letter grades for coursework. An ordinal variable is similar to a categorical variable, but the difference between the two is that there is a clear ordering of the categories. For example, suppose you have a variable, economic status, with three categories (low, medium, and high). In addition to being able to classify people into these three categories, you can order the categories as low, medium, and high.