Make data accessible
By designing data and data visualisations in an accessible way we are making things better for everyone, and we will have a better chance of using our data analysis to influence change.
Guidelines
Some guidelines to follow when visualising data:
- Don’t use colour alone to visualise information. Roughly 4.5% of the population suffer from sort of colour deficiency. Consider limiting your colour choices to four, and using direct labels or varied symbols and line styles
- Test your colours for accessibility. This includes testing the contrast of text on block colours, for example data labels on charts
- Label data directly rather than using data legends
- Keep it simple and pick the most simple chart for your visualisation
- Provide good alt text to images and charts. Good alt text should describe the information not the picture and focus on the key thing the chart communicates
- Test and iterate. Test how your visualisation looks on mobile or zoomed in. Consider what the user can see on a particular viewpoint - for example if there is too much white space
- Where possible, provide a link to the underlying data source as a table or sheet. Be aware that read only access to a Google Sheet doesn’t always unlock accessibility features so consider sharing sheets with edit permissions
Resources
Useful resources on data accessibility
- Communicating analysis - Government Analysis Function guidance
- Data visualisation - ONS style guide
- Presenting data: 5 tips for making your data accessible - Data in Government Blog
- Releasing statistics in spreadsheets - Government Analysis Function guidance
- Writing Alt Text for Data Visualization - Medium article
- A plan for accessible charts - blog
- Best Practices for Designing Accessible Views (including good and bad examples of accessibility) - Tableau help article
Accessibility resources
- GDS accessibility blog
- Cross-government accessibility community
- Accessibility guidance in the service manual
- Assistive technology you can test with (free) - Accessibility in government blog post
- GOV.UK assistive technology survey - Accessibility in government blog post
This page was last reviewed on 14 August 2024.
It needs to be reviewed again on 14 February 2025
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