A dot plot shows one or more quantitative values per category by plotting one or more dots per category on a numerical (or date-time) axis. A dot plot with only one value per category makes a comparison between those categories very easy. When the dot plot has multiple values per category, you can also compare within the categories. This results in a chart type that packs a lot of information in a small space.
Since the dots communicate information via their position on the axis, and relatively via their position towards each other, the start- and end-point of the axis should be based on the minimum and maximum values in the data. There is no need to start the axis at zero.
By adding a connector between the dots, you can add an extra dimension to an already information-dense chart: The connector adds a focus on the delta between two values or the range between a minimum and maximum value.
The most simple alternative to a dot plot is a bar (or column) chart. Instead of using relative position on the numerical axis, the bar chart uses the length of the bar to communicate the value. To replace multi-series dot plots, one can choose between a stacked or a grouped bar chart. This makes comparison within and between categories possible.
Gridlines are what turns a set of barbells into an actual chart with a proper context.
Read moreA dot plot can be a pretty simple chart. Its minimum pack is categorical and numerical dimensions and a fixed size mark. Color is the thing that adds the edge to this chart. It might be used to place simple accents, but it can also add a new dimension: numerical, categorical, or even time.
Read moreSort the categories in the data. Either based on the highest value, the lowest value, or the delta.
Read moreCombining a dot plot with another chart is a perfect choice for showing more context which may otherwise not be apparent.
Read moreUsing data labels instead of numerical axis makes the chart cleaner and gives full information about dot values.
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