A categorical variable may also consist of more than two categories. For example, a person's major in college can be categorized as biology, history, engineering, psychology, etc. A categorical variable can be ordered or unordered . Although the levels of a categorical variable are often represented by numerals, these symbols are not interpreted numerically if the variable is unordered. In this document, we assume variables are unordered unless otherwise specified.
Additional techniques are possible with ordered data.
Please see a consultant for more help if you wish to investigate other types of analyses not covered in this document. Categorical data are often presented in a contingency table which tabulates the number of observations that fall into each cell of the table. Table 1 is a simple 2 x 2 contingency table that crosstabulates whether graduate school applicants were accepted or rejected and whether they were male or female. Each cell represents a joint event which is a unique combination of the categorical variables. The crosstabulation of the graduate school's decision and applicant's gender results in four possible outcomes, or joint events.