Introduction
Tables and charts must be built in an accessible way to ensure that people using screen readers can understand the structure and meaning of the data. Proper formatting also helps everyone to navigate and interpret the information clearly, regardless of whether they have an impairment or not.
When adding charts into your document, an important thing to keep in mind is that some people cannot see colour. You cannot use colour alone to convey meaning. For example bar charts must have textures as well. This is so that someone who cannot see the colours can still tell the difference between the data sets. There must also be a clear key to explain which colour and texture belongs to which data set.
Why it matters
If a table does not have a header, a screen reader may read the data without context. This makes it difficult or impossible for users to understand what each cell or chart area represents. This can lead to confusion, especially when the data is complex, as users will not know which data belongs to which category.
How to do it
Tables
To add an accessible table in Word:
- Insert the table by choosing ‘Insert’ then ‘Table’
- Use clear header titles in the top row
- Select the top row, then go to ‘Table Design’ then ‘Header Row’ to mark it as a header
- Avoid merging or splitting cells because assistive technology cannot read them
- Add a table title or caption above the table in the document to describe its purpose
Charts
To add an accessible chart in Word:
- First choose ‘Insert’ then ‘Chart’, choose your chart type, and click ‘OK’
- To add descriptive Alt Text right-click the chart and select ‘Edit Alt Text’
- Write a brief summary of the chart’s key message or trend
- If the chart is decorative, check ‘Mark as decorative’
- Always include the Data Table
- Add a table below or near the chart with the same data
- Use clear headers and do not merge any cells
- Use High Contrast and Labels
- Make sure colours are easy to distinguish from each other, use a variety of tones and hues
- Do not rely on colour alone, always add data labels or patterns