ABSTRACT
The simplest type of measurement is called the nominal scale where observations are allocated to one of various categories. Examples of nominal data with only two categories (binary) are: male/female, winners/ losers or presence/absence of a disease. Examples of nominal data with more than two unordered categories are: country of birth, favourite sport, team supported and different equipment manufacturers. As long as the categories are exhaustive (include all cases) and non-overlapping or mutually exclusive (no case is in more than one category), we have the minimal conditions necessary for the application of statistical procedures on observations categorised on a nominal scale.
