Definition
Turning to the authority of introductory statistical textbooks (Bluman 1992; Samuels and Witmer 1999), there are two parallel ways to classify data into different types. Data can be classified into either categorical or numeric. Data can also be classified into different levels of measurement scales.
There are two parallel ways to classify data into different types. Data can be classified into either categorical or numeric. Data can also be classified into different levels of measurement scales.
Categorical versus Numeric
Variables can be classified as either categorical or numeric. Categorical variables, also often referred to as qualitative variables, are variables that can be placed into distinct categories according to some characteristics. Categorical variables sometimes can be arrayed in a meaningful rank order. But no arithmetic operations can be applied to them. Examples of categorical variables are
-
Gender of a fish: male and female
-
Student evaluation: fail, pass,...