Tables are a useful way to display large amounts of data. A well-designed table can present information in an ordered and understandable manner for a wide range of users. However, for students who are blind, tables can be challenging if they are not designed properly. Most (but not all) programs have built in functions that make it easy to ensure that your tables are easily read and understood by all.
Things to keep in mind
- Adding some brief descriptive text directly before the table is useful to let the user know what the upcoming table is about.
- Always identify (tag) the row and column headings so that a screen reader can tell the user what each cell is referencing.
- Note: Google Docs does not have a way to add column and row header tags to tables within a document. Try to avoid using tables in Google docs.
- Don’t merge (or span) cells in a table in Microsoft Word – it confuses screen readers and makes navigation difficult.
- You can merge cells in Excel and Adobe PDFs – just be sure to identify the span and scope of the merged cells.
- Don’t leave blank cells in a table – a screen reader user will not know if the information is missing or if it is a style choice.
- Never use tables for layout In Microsoft Word and PowerPoint. Use tables to display information only. Screen readers may not be able to recognize headings and other important markers in a table cell.
- While you can use tables for layout in HTML, you will want to make sure that this doesn’t affect the order or understanding for someone using a screen reader. The WebAIM creating accessible tables article has some excellent advice on this.
- Shading the background of different cells can make some tables easier to read and can highlight useful information. However, choose colors that provide adequate contrast and make sure the information is still understandable without color. See Color for more information
Tips and Tricks
- Screen readers read tables left to right from top row to bottom. Look at the information in the cells – does it make sense in that order?
- People who are blind don’t use a mouse – can you navigate correctly through the table using only your tab key?
- If you need to have blank cells for visual clarity/aesthetics – you can indicate that the cell is intentionally blank by writing in that cell (e.g. “empty cell”, “no data”, “missing data” “blank” etc…) then change the color of the text to match the background. The cell will visually look blank but will not confuse screen reader users.
- Although many programs give you the option, you do not have to add alternative text to a table. If you have designed it to be accessible, the student can get all of the necessary information from the table itself.
- In programs that do not give you the option to tag the column and row headers, you can convert the document to a PDF and tag it there.