Glossary · Accessibility term
Cognitive disability
Cognitive disability is a broad group of conditions affecting how people take information in, hold on to it, and act on it. It covers reduced ability in areas like reading, writing, communication or number work, difficulty understanding new or complex information, and reduced memory and attention. Intellectual disabilities, dyslexia, ADHD, autism, brain injury after a stroke or a concussion, early-stage dementia, and mental health conditions such as anxiety all sit inside it, and W3C's own scope for this area names neurodiversity alongside them. One thing is worth saying plainly, because it is the most common misconception about the whole category. Overall intelligence is often not affected at all. Everybody has bad days with a confusing interface, and what makes this a disability is that the difficulty is persistent and significant enough to stop somebody finishing the task on their own.
In practice
What helps is unglamorous and almost none of it is expensive. Plain language. Predictable layouts and consistent navigation. Error messages saying what to do next rather than naming a rule. No surprise time limits. Not asking somebody to remember something from a screen they have already left. W3C organizes its guidance for this group into eight objectives, and two of them get skipped most often. Making it easy to reach a human, and supporting the tools people bring with them.
Those tools are browser extensions and add-ons, which are the assistive technology for this group and the ones most lists forget. People use them to reformat pages, simplify text, mask distractions and read aloud. W3C's instruction to authors about them is one line long. Do not disable add-ons and extensions.
WCAG has more to say here than it used to, which changes the old complaint that none of this has a rule attached. Version 2.2 added three criteria aimed squarely at this group, and each is narrower than its headline. Consistent Help never asks you to offer help at all. It asks that the help you do repeat across pages keeps the same place in the running order. Redundant Entry covers information asked for twice inside one process, and it lets you ask again where re-entering is essential, where security needs it, or where the earlier answer has expired. Accessible Authentication bars a memory or puzzle test at login unless the step offers one of four things, another way in among them. The first two sit at Level A and the third at Level AA.
Why it matters
This is where the conformance checklist runs out first. A great deal of what helps here resists being written as a testable rule, so a team working strictly to a list does the parts with a criterion attached and stops. The tension runs the other way too, and it is a real one. Some people with cognitive disabilities need lower-contrast color combinations, and the standard allows exactly that as long as a mechanism can put the required values back. Maximum contrast is not universally good, and no single setting is, which is why the answer here is so often to let people adjust rather than to choose for them.
What tends to break
A flat page where blocks of content run into each other, so working out which parts belong together is guesswork. A menu whose sub-items only appear once you have found them by accident. A percentage where a plain count would do. A session that expires without warning. None of those shows up as an accessibility bug in a scan, and every one of them costs somebody the task.
Where this shows up on the site
Related terms
- Plain languagePlain language is writing that lets somebody find what they need, understand it the first time, and act on it.
- DyslexiaDyslexia is a set of processing difficulties that affect the acquisition of reading and spelling.
- TimeoutA timeout is a time limit the content sets, such as a session that expires, a booking held for ten minutes, or a form that clears itself after a while.
- Error identificationError identification is the Level A rule that when your form rejects something, the page names the field that failed and says in text what went wrong.
- CAPTCHAA CAPTCHA is a test a site puts in front of you to prove you are a person and not a program.
Knowing the word is the easy part.
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