What is accessibility
Since September 2020, by order of the The Public Sector Bodies (Websites and Mobile Applications) (No. 2) Accessibility Regulations 2018, everything we publish on GOV.UK must be as accessible as possible for all users. These include:
- the blind, who are entirely reliant on screen readers to understand every aspect of the content we publish, including the structure of text, the structure of tables and the meaning of all visual elements
- the partially sighted, who struggle with small text, footnotes and symbols and visual elements - around 360,000 people in the UK are registered as blind or partially sighted, with almost 2 million living with some kind of sight loss
- the colour blind or, to use the correct term, the colour vision deficient, who don't see colour in the traditional way so that we must never rely on colour alone to convey information
- dyslexics (10 million or 6% of the population) which is why we avoid the use of bold, italics and unnecessary capitals
Spreadsheets and accessibility
Like all other content published on GOV.UK, all spreadsheets we publish must be as accessible as possible.
Government Digital Service (GDS) guidance defers to the Government Statistical Service (GSS) who are experts in this area.
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This is the example GSS give of an accessible spreadsheet. Note how plain, uncluttered and undesigned it is, with no logos, pictures, graphs or colours. Just a title for each worksheet, few sentences of explanation and key information, then simple, uncluttered tables with no merged cells and one header row.
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Spreadsheets are for data tables, not text
Spreadsheets are solely should only be used for data.
A spreadsheet must not contain large amounts of text. If you wish to present large amounts of textual information, please publish this should be published as a separate HTML web page or attachment.
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In reality many tables are created with multiple header rows which often feature merged cells. Here are some common problem layouts and fixes.
1. If a merged cell contains information, the information can be cut and pasted into a description cell above. On close examination, the information in the parent row often repeats the table title and so is redundant.
In this example the merged top row which simply says 2020/21 is either already implicit in the table title, or could be cut and pasted out into a row directly above the table explaining that these are results for 2020 to 2021.
So that it now has only two heading rows - still undesirable, as are the merged cells sitting above the individual columns.
2. If a merged header cell sits above sub-headers, the 'parent' header title can be incorporated into each of the sub-headers and the overarching row deleted. So in the this example above, the phrases 'Response summary' and 'vaccine uptake' can be pasted into the 'child' header rows below, thus:
With three header rows the table was impossible to mark up as a table. Now, with only one header row, it can be marked up. All all that remains is to mark it up (as explained above) and make a few cosmetic and formatting syle changes:
- remove colour
- left justify title (making it heading 1) and the sub-title
- write a description sentence
- remove bold except for header row
3. If there are only 2 or 3 tables with merged parent headings, they can be divided into smaller tables.
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In whatever format notes are indicated, an explanation should be given in the description text in the second or third row, for example: ‘This worksheet contains one table. Some cells refer to notes which can be found on the notes worksheet/at the end of the relevant row’.
Graphs in spreadsheets
Ideally, spreadsheets should not contain graphs or charts but be limited to tables of data.
If graphs are included, note that graphs are free-floating elements in a spreadsheet and so not tied to the logic of the main content, so their positioning does not affect the order they're read in by a screen reader.
Given this fact, it is probably best to position graphs close to the source table, probably to the right of it if its not too wide.
1. Save graphs as interactive and not as flat images because some screen readers can read every element i.e. every bar of a bar chart.
2. Give graphs alt text. Alt text is deprecated in HTML web pages or PDFs because a written text summary can be placed directly above or below the image to explain it. But since graphs float free in spreadsheets this approach does not apply.
Colour
Avoid all colour, for any reason. Everything should be back text on plain white background for maximum accessibility.
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