When people talk about digital accessibility they mostly think of sight and the use of the hands: screen readers, contrast, keyboards. There is, however, an equally large and less discussed area: cognition. It concerns people with dyslexia, attention disorders, memory difficulties, intellectual disabilities, the effects of brain injuries and age-related cognitive decline. And at certain moments it concerns everyone: people who are tired, stressed, distracted, ill, or using a service for the first time.
The underlying principle is simple: every interface asks the user for mental effort. Reducing unnecessary effort makes a product usable by more people and more pleasant for everyone.
Cognitive load
Working memory, the memory we use to keep things in mind while doing something else, has a limited capacity. An interface that forces you to remember a code read on the previous page, compare options scattered across different screens or interpret ambiguous icons overloads it.
Some typical sources of unnecessary load:
- too many choices presented all at once;
- necessary information that disappears when you move on to the next step;
- elements that flash, move or update while you are reading;
- terminology that changes from one page to another for the same thing;
- long instructions to read before you can even start.
Design principles
Recognition rather than recall
This is one of the classic usability heuristics, and it is central to cognitive accessibility. Show the available options instead of asking people to type them, summarise the data entered before confirmation, keep the context visible. A cart that remembers the products chosen, a process that shows which step you have reached, a field that suggests possible values.
Consistency
The same button in the same place, the same word for the same action, the same structure on every page. WCAG asks for this explicitly in its criteria on consistent navigation and consistent identification. For people who find it hard to learn new patterns, every inconsistency is a new puzzle.
One step at a time
A long form split into short steps, each with a clear heading, is less intimidating than an endless page. It also matters to show how many steps are left: knowing what to expect reduces anxiety.
Enough time
Time limits, such as a session that expires or a code that must be entered within a few seconds, penalise people who read slowly or need to reread. WCAG criterion 2.2.1 requires that users can turn off, adjust or extend time limits, with exceptions such as real-time auctions. A simple warning, «Your session is about to expire: do you need more time?», solves many cases.
Protect against errors
People who are distracted or tired make more mistakes. Confirmation before irreversible actions, the ability to undo, automatic saving of entered data and error messages that explain how to fix the problem are all valuable safeguards.
What is new in WCAG 2.2
Version 2.2 of WCAG introduced some criteria that directly address cognitive aspects:
| Criterion | Level | What it requires |
|---|---|---|
| 3.2.6 Consistent Help | A | If there are help mechanisms, such as contact details or chat, they must be in the same place on every page |
| 3.3.7 Redundant Entry | A | Do not ask people to re-enter information already provided in the same process, except for justified reasons |
| 3.3.8 Accessible Authentication (Minimum) | AA | Do not impose cognitive tests, such as remembering a password or solving a puzzle, without an alternative |
The last point is interesting: blocking paste in a login password field forces people to remember it or copy it character by character, which is exactly the kind of obstacle the criterion is meant to prevent. Allowing paste and password manager autofill helps both accessibility and security.
Dyslexia and reading
For people with dyslexia, reading takes more energy. A few measures help in practice:
- left-aligned rather than justified text, to avoid irregular gaps between words;
- lines that are not too long and generous line spacing;
- avoiding long blocks of italics or all capitals;
- short sentences and a clear structure with headings and lists;
- the ability to enlarge text without breaking the layout.
There is no typeface that solves dyslexia on its own; spacing, line length and clear writing matter more.
Distractions and attention
For people with attention difficulties, moving elements are a serious problem: auto-advancing carousels, videos that start on their own, animated banners, constant notifications. WCAG criterion 2.2.2 requires that moving content lasting more than five seconds can be paused, stopped or hidden. Better still is not to start it automatically.
How to check
In my work I find a simple exercise useful: use the service after a long day, or have someone try it while being interrupted now and then with a question. Where people get lost, where they have to go back to look for information, where they are afraid of making a mistake: that is where there is cognitive load to reduce. The next step, where possible, is to involve people with cognitive disabilities in testing.
In short
- Cognitive accessibility concerns many people with disabilities and, in moments of fatigue or stress, everyone.
- Reduce the load on memory: show options, summaries and context instead of asking people to remember.
- Consistency, step-by-step processes and adequate time limits lower effort and anxiety.
- WCAG 2.2 calls for consistent help, no re-entering of data and logins without mandatory cognitive tests.
- Movement and automatic distractions should be limited and made controllable.
