Data Scientists use displays to visualize data. You’ve probably seen some of these charts, graphs and plots yourselves! When it comes to displaying Categorical Data, there are two displays that are especially useful.

  1. Bar charts show the count or percentage of rows in each category.

    • Bar charts provide a visual representation of the frequency of values in a categorical column.

    • Bar charts have a bar for every category in a column.

    • The more rows in a category, the taller the bar.

    • Bars in a bar chart can be show in any order, without changing the meaning of the chart. However, bars are usually shown in some sensible order (bars for the number of orders for different t-shirt sizes might be presented in order of smallest to largest shirt).

  2. Pie charts show the percentage of rows in each category.

    • Pie charts provide a visual representation of the relative frequency of values in a categorical column.

    • Pie charts have a slice for every category in a column.

    • The more rows in a category, the larger the slice.

    • Slices in a pie chart can be shown in any order, without changing the meaning of the chart. However, slices are usually shown in some sensible order (e.g. slices might be shown in alphabetical order or from the smallest to largest slice).

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