Laws of Perception · cognitive-bias
Working Memory
Playable Play this law (~3 min)or keep reading below ↓
Users can hold only a few items in mind for a few seconds while acting. Any design that makes people remember information from one screen to use on another — codes, prices, option names — is spending their scarcest resource.
Where it comes from
Alan Baddeley and Graham Hitch proposed the working-memory model in 1974 at the University of Stirling, replacing the idea of one short-term store with a small active workspace that both holds and manipulates information — and overflows fast. It's why waiters write orders down and pilots read checklists aloud: offloading beats remembering. Interfaces should be the notepad, not the test.
Origin: Baddeley & Hitch's 1974 working-memory experiments
In the wild
- OTP inputs
Good flows read the SMS code automatically or keep it visible while typing; bad ones make you memorise 6 digits across an app switch.
- Comparison pages
Side-by-side plan tables exist because nobody can hold plan A's limits in mind while reading plan B.
- Multi-step wizards
Showing your earlier choices in a summary rail spares users from re-remembering what they picked.
Further reading
Don't just read it — feel it.
Play the 3-minute game and let your own reactions prove the law.
Play the lesson