Graphing Nominal Data

Graphing nominal data typically involves using bar charts, pie charts, or dot plots. These charts display data categories (like colors, names, or types) without implying any order or numerical value.

For graphing nominal data, the goal is to visually represent the frequency or proportion of categories. Here are some effective options for displaying nominal data:

Bar Chart

A bar chart uses rectangular bars to represent the frequency or count of each category. Each bar’s height (or length if horizontal) corresponds to the number of occurrences or the proportion of each category.  Bar charts are easy to understand and are ideal for comparing the frequencies of different categories. They work well when there are a limited number of categories.  Generally, bar charts are the most versatile and commonly used option for nominal data.

Pie Chart

A pie chart shows the proportion of each category as a slice of a circle. The size of each slice corresponds to the category’s proportion of the total. Pie charts are useful for illustrating the relative proportions or percentages of categories within a whole.  Best used when you want to emphasize the proportion of each category relative to the total (e.g., market share of different brands, responses to a yes/no question).

Donut Chart

A donut chart is similar to a pie chart but with a hole in the center, often used to present nominal data proportions.  Donut charts can be visually appealing and can also include a central label that adds additional information. Like pie charts, they are best used for showing the relative proportions of nominal categories.

The following tutorial covers how to create bar, pie, and donut charts in Excel and in Google Sheets: 

Stacked Bar Chart