Types of Variables

Categorical or qualitative data are the result of categorizing or describing attributes of a population. Categorical data are often words, but can also be numerical like in the case of “Grade Level”, “ZIP Code”, or other numbers used to categorize groups rather than quantify them.

On the other hand, quantitative data are always numbers. Quantitative data are the result of counting or measuring attributes of a population.

Quantitative data can further be described as discrete or continuous depending on the types of values the variable can take.

• Quantitative discrete variables take on a limited set of values, such as counting numbers (such as 1, 2, 3…) with no values in between.
• Quantitative continuous variables can take on any value within a range.