This refers to the observed distribution of any given variable. Put differently, this is a way of understanding how observations are distributed in our specific sample.

Categorical variables

• Observations are spread across a set of categories.
• The primary interest is usually to describe the percentage of observations found across the categories (percentage distribution).
• Typically, we describe the distribution of categorical variables with frequency tables, pie charts, and bar charts.

Continuous variables

• Observations are spread across a range of values.
• The primary interest is usually to describe the frequency (number) of observations found across the values (frequency distribution).
• Typically, we describe the distribution of continuous variables with histograms as well as measures of central tendency and variation.

Note We will go further through alternatives for describing the distribution of categorical and continuous variables in the chapter Descriptive analysis.