Cognitive psychology quiz

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

Cognitive load

The mental effort required to complete a task. Too much and people slow down, make mistakes, or quit.

Hick's law

The more choices you offer, the longer a decision takes - and the cost grows logarithmically, not linearly. Choices take time, not just space.

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 easier than recalling it from scratch. Good interfaces give you choices - menus, icons, recent items, autocomplete - instead of forcing you to remember and type from nothing.

Serial position effect

When recalling a list, items at the start and end are remembered better than those in the middle. It’s not what’s on the list, but where it sits, that affects memory.

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 group stands out, it’s more likely to be remembered. Its uniqueness acts as a memory cue: the odd one out captures attention, whether it wants to or not.

Miller's law

Working memory holds about seven items at once, plus or minus two. Beyond that, things start to slip. It’s not about how smart you are - it’s about the mental space you’ve got.

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.

Selective attention

Selective attention means your mind focuses on what you’re actively looking for and overlooks everything else - even obvious things right in front of you. When deeply concentrated, you’ll often miss the most noticeable item on screen.

Choice overload

Choice overload (the paradox of choice) is when too many options make a decision harder, not easier - people take longer, feel less sure, regret more, and sometimes don't choose at all. It's more than Hick's extra seconds: it's the weight of the options themselves.

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 its average. Instead, we remember it mostly by its most intense moment and how it ended - and we tend to ignore how long it lasted.

Hick's law vs Miller's law

Both are about "how many", but they measure different things. Hick's law is about choosing - decision time grows with the number of options. Miller's law is about holding - working memory keeps only about seven chunks at once. One is speed of choice; the other is capacity of memory.

Confirmation bias

Confirmation bias is the pull to notice, trust and remember whatever fits what you already believe - and to wave away whatever does not. It quietly turns research into a hunt for "yes" rather than an honest test of "is this true?".

Dunning-Kruger effect

The Dunning-Kruger effect is the gap between how good people think they are and how good they actually are - widest at the bottom, where knowing too little to spot your own mistakes leaves you oddly confident. The less you know, the less you know it.