Thoughts

A 5 Step Guide to Accessible Data Visualizations

How simple details can make data visualizations more accessible

A large number of business graphs and charts in three-dimensional space.

As analysts, the reason we spend time creating data visualizations is to communicate information. But what if the information you’re trying to communicate isn’t accessible? By paying attention to a few specific details, you can easily increase the accessibility of your data visualizations and communicate your insights to more people.

Starting with the default chart below that was generated in Excel, we will make 5 small adjustments, and we will end up with a much more accessible visualization.

Chart 1 – Starting Chart

A line graph titled “Sales by Product” with units sold by month. Product A is mostly constant. Product B increases.

1. Describe the main takeaway in text

Left-aligned, descriptive, text-based titles and subtitles communicate the most important information found in the visual.

Chart 2 – First Change

Product B’s performance has overtaken Product A

Same chart as above. The title has been removed, and a more descriptive title is displayed in text above the image.

Product B’s sales increased steadily and since November have been higher than Product A, our consistent high-seller.

2. Don’t rely solely on color to differentiate data

Use features like fill patterns and icon shapes to differentiate data, instead of only using color. This will make your visualizations understandable to folks with colorblindness – and when it is printed in black and white!

Chart 3 – Second Change

Product B’s performance has overtaken Product A

Same chart as above. The points of one line are marked with circles and the other with squares.

3. Pick your colors intentionally

Choose colors with good contrast to the background, and when in doubt, use fewer colors rather than more. Colors can be used selectively to highlight the information that is important.

Chart 4 – Third Change

Product B’s performance has overtaken Product A

Same chart as above. Product B is now shown in dark blue and Product A in gray. The blue draws the eye first.

4. Use whitespace to separate elements

Adding whitespace helps folks with low vision separate different data series and can help clarify intersecting lines on a line graph.

Chart 5 – Fourth Change

Product B’s performance has overtaken Product A

Same chart as above. A red arrow points to where the two lines intersect. The lines now have a white outline.

5. Label data series directly

By labeling data series directly, rather than using a key set off to the side, the viewer’s eyes do not have to bounce between two regions on the chart in order to understand which data belongs to which series.

Chart 6 – Ending Chart

Product B’s performance has overtaken Product A

Same chart as above. Instead of the legend, the series labels are placed next to the corresponding data in a matching font color.

Imagine your data visualizations reaching everyone, not just a select few. By following a few simple design principles, you can make that a reality. Not only will you be doing your job better, but you’ll also be contributing to a more equitable and informed society. It’s time to make your data visualizations more accessible.

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