Nominal variables do not have an inherent numeric order to their categories, therefore some other basis is needed for determining how to arrange those categories in tables, charts, and prose. For instance, it isn’t obvious in which order to list geographic regions, ethnic group, or gender.

Likewise, for a series of items such as symptoms, causes of death, or barriers to prenatal care, there is no “natural” order in which to organize them in a table or chart.

For more information on types of variables, see Chambliss, Daniel F. and Russell K. Schutt. 2003. Making Sense of the Social World: Methods of Investigation. Thousand Oaks, CA: Sage Publications.