Frequency tables are usually produced on individual variables. For categorical data, the table records the number of observations (i.e. the frequency) for each unique value of the variable. For continuous data, It must specify set of intervals . The frequency table records the number of observations falling in each interval. Frequency tables are useful for analyzing categorical data and for screening data for data entry errors.

Two types of variables may be specified to be used in rows and columns: Categorical Variables and Numeric Variables.

Categorical Variables

Categorical variables may include text values (e.g. “Male, Female”) or index numbers (e.g. “1, 4, 7, 15” to represent 4 states). The numbers or categories may be ordinal (e.g. “Low, Medium, High” or “1, 2, 3, 4, 5” as in a Likert scale).

• Numeric Variables

Since contingency tables display categorical data, all numeric variables with continuous data must be grouped into categories by the procedure using user-specified rules before the table is created.