STAT-151 Lecture Notes - Lecture 2: Macewan University, Sylvia Fedoruk, Categorical Variable
Document Summary
In order to obtain data, one must first identify variables of interest. The data then correspond to particular realizations of said variables. A variable is a characteristic/condition that varies for different individuals/observations, i. e. height, weight, g. p. a. , gender, number of times visited by aliens, etc. There are two types of variables, measured as qualitative and quantitative data. Qualitative (categorical): does not assume a numerical value but rather, is classifiable into 2 or more non-numeric, distinct, categorical values, i. e. gender (male, female, other), smell (stinky, neutral, fresh, old spice fresh), etc. When there is ordering among the levels of a categorical variable, the variable is said to be ordinal; when no such ordering exists, the variable is called nominal. In a qualitative dataset, the number of times a particular, distinct value occurs is referred to as its frequency or count. A frequency distribution of qualitative data is a listing of the distinct values and their frequencies.
