Accessibility

This section of the guidelines outlines best practices for creating accessible data visualizations.

Federally-funded agencies are required to make their content accessible to people with disabilities. In the U.S. 26% of adults have some type of disability, with about 19% of adults in Connecticut having a disability.1

The Center for Disease Control and Prevention (CDC) defines a disability as any condition of the body or mind (impairment) that makes it more difficult for the person with the condition to do certain activities (activity limitation) and interact with the world around them (participation restrictions).

We should all prioritize accessibility from the start of our data visualization process and should consider hearing, motor, cognitive, and visual accessibility. Use these guidelines as a starting place for designing accessible data visualizations.

Table of Contents

Data
  1. Provide an accessible table format
  2. Use familiar data visualizations
Color
  1. Don’t use color as the only way to convey information
  2. Ensure that there is enough contrast between colors
  3. Choose colorblind friendly color palettes
  4. Use white space
Text
  1. Provide a text-based equivalent for every viz
  2. Use alt text to describe all non-decorative visuals
  3. Use plain language
  4. Ensure text is readable
  5. Use meaningful labels and titles
Interaction
  1. Make your visualizations keyboard-accessible
  2. Ensure the keyboard focus indicator is visible
  3. Check that the tab order is logical
  4. Don’t require interactions to access key information
Testing
  1. Test your viz with a screen reader
  2. Test for low vision
  3. Test on mobile

  1. CT.gov Content Style Guide, Accessibility Best Practices, https://portal.ct.gov/ctcontentstyleguide/improve-accessibility/accessibility-best-practices ↩