Stats

Categorical Variables

Variables that place individuals into one of several groups or categories.

Bar Graph

A graph that displays the count of different categories, comparing the heights of bars.

Pie Chart

A chart that displays the percentage of different categories within a whole.

Marginal Distribution

The distribution of values of a variable among all individuals described by a two-way table.

Two-Way Table

A table that describes two categorical variables, organizing counts according to a row variable and a column variable.

Conditional Distribution

Describes the values of a variable among individuals who have a specific value of another variable.

How to examine Marginal Distribution?

1. Calculate the marginal distribution (%) of the row or column totals. 2. Make a graph to display the marginal distribution.

How to examine Conditional Distributions?

1. Select the row(s) or column(s) of interest. 2. Calculate the conditional distribution (%) of the selected row(s) or column(s). 3. Make a graph to display the conditional distribution.

Relationships Between Categorical Variables

Describes how variables relate by examining conditional distributions.

Segment Bar Graph

A graph used to compare distributions by showing segments within a single bar for each category.

Side by Side Bar Graph

A method of comparing distributions by placing bars of different categories side by side.