Evaluation method: The Sample
What pages to collect for a sample if you are going to evaluate a website on accessibility. Before you start you must have the domain or list of domains on which the audit should take place.
Compile a sample
Common pages
- Homepage
- Contact
- Sitemap
- Search page/search result
- Page with video (media)
- Page with iframe
- Page with data table
- Form (i.e. contactform)
- Other language (page and/or part of page)
- 404 page
- Page with the accessibility statement
Essential functionality
Look for the top tasks (often the most notable links on the homepage). If top tasks are hosted on a different domain then check if these top tasks are under supervision of your client. Also check if some functionality is not already tested and a report is available.
Customer request
Sometimes a website owner wants some certain pages in the sample. Add them now if they are not yet in the sample.
Variety of content types
Next try to find different kind of pages. Pages that uses different kind of template types. For instance a page with a News overview and a News item
Recognize other techniques
If there are any PDF's add at least 2 PDF files to the sample. Check if the files come from a domain that is in the scope of this evaluation. 1 PDF file is considered as 1 page.
Check for other techniques.
Random pages
It is required to select 2 random pages (I've created a URL randomizer).
Minimum sample
A sample needs at least 12 pages. Every PDF file counts as 1 page. First follow the undocumented steps.
| Volume | Size sample |
|---|---|
| 0-300 pages | 12 |
| 300-1000 pages | 14 |
| 1000-5000 pages | 16 |
| Every 5000 pages | +2 |
| Every other content file format | +2 |
| Pages in a proces | no limitations |
Undocumented sampling
If non-unique titles of pages exist do add 2 different pages with the same title to the sample, so you can test for SC 2.4.2. Duplicate titles can be found manually via tools like Screaming Frog. If there are duplicate titles also check if pages are marked as canonical which means that those pages don't count as duplicate.
With an automatic test on accessibility you can search for uncommon issues. If none of the pages where an issue occurs are in the sample, select one of these pages.
If subdomains are involved in the sample I usually start with at least 2 pages per subdomain.
