Cognitive psychology quiz

The cognitive psychology entries in the glossary, in brief. Open any one for the interactive demo behind it.

Cognitive load

The total mental effort a task demands. Pile on too much and people slow down, make mistakes, or give up.

Hick's law

The more choices you offer, the longer a decision takes - and it climbs with the logarithm of the number of options, not in a straight line. Choices carry a time cost, not just a space cost.

Mental model

The picture in someone's head of how a thing works. When the interface matches it, everything feels obvious; when it doesn't, nothing does.

Recognition vs recall

Recognising something you're shown is far easier than recalling it from a blank memory. Good interfaces show the options instead of making you remember them.

Serial position effect

When you try to remember a list, the items at the start and the end stick, and the ones in the middle slip away. Position on the list, not just the item itself, decides what you keep.

Chunking

Chunking is the brain's trick of grouping individual pieces of information into meaningful units, so instead of memorising twelve separate digits, you hold three groups of four. The chunk is the unit, not the items inside it.

Von Restorff effect

When one item in a list is noticeably different from the others, it sticks in memory far better than its neighbours. Distinctiveness is a memory signal: the odd one out earns attention it didn't ask for.

Miller's law

Working memory can hold roughly seven items, plus or minus two, at once. Exceed that limit and things start to fall out. The constraint isn't about intelligence; it's about the size of the mental workspace everyone is working with.

Change blindness

We are surprisingly blind to changes that happen during a flicker, reload or blink. Without an unbroken motion cue, even a big change can sit in plain sight until you go hunting for it.

Zeigarnik effect

We remember - and keep feeling pulled towards - tasks we've started but not finished. An open loop sits in working memory and nags for attention until you close it; the moment you complete it, the mind quietly lets go.

Peak-end rule

We don't judge an experience by averaging every moment of it. We remember it mostly by two points - how it felt at its most intense (the peak) and how it felt at the end - and we quietly discount how long it lasted.