A great practice to follow is providing your users with a text description of the chart or graph. The text description can also serve as the chart’s or graph's summary — and this addresses a significant caveat of data visualization: not only beautifully presenting the data but helping the user conclude. Although the story the data tell may seem self-evident to the chart’s or graph's author, the viewer, on the other hand, may struggle to connect the dots: “Value A has been on the rise throughout the last four years, but decreased significantly in the previous quarter."
When creating charts or graphs, you want to make them as accessible as possible.
If your graph or chart has been included in your document or as an image, you must ensure that you have included alt text for the image.
Alt Text and Descriptions
In your alt text, summarize what is going on in your graph, what conclusions someone can draw from this figure, and why it was important enough to include in your work. Increase the accessibility of your charts by including tabular data in addition to your chart or graph. This allows users who are accessing your information with a screen reader to have still a way to navigate through your information without missing out on anything.
Do your best to keep your description to less than 80-100 characters. Some screen readers are incompatible with longer alt-text descriptions.
Right Click on the chart, graph, or table and select "Edit Alt Text..."
Fill in the information into the newly opened field.
Charts and graphs display complicated information as a visual, and it can be hard to conceptualize what is going on in a graph if you are only presented with a list of numbers in a table. Adding a text description to your audience can help your visually impaired and sighted users better understand and interpret your information:
- Why your graph, chart, or table is important
- What is important: What is the main idea? What do you want your audience to understand?
- How is this important in context?
Keep Things Simple!
A chart, graph, or table should be simple. Try to keep your data as clear and concise as possible!
Some things you should look for are:
- How to Create Accessible Tables
- A basic and accessible color scheme with Good Contrast.
Additional Resources:
The following links will help you learn more about creating accessible charts, graphs, and tables:
- General image description guidelines
- Specific image description guidelines
- Accessible Digital Charts, Graphs, and Maps!
- Create more accessible charts in Excel - Microsoft Support
- Provide access to graphs for users who are blind or visually impaired (WGBH Article)
- Describing Science Images for Learners with Disabilities (WGBH Article)