Topic
Cognitive psychology
Nearly every rule of thumb in UX is really a fact about the mind, borrowed and put to work. How much someone can hold in their head at once, what they notice and what slips past, how they expect a thing to behave before they have even touched it - all of it is set by how attention and memory actually work, long before anyone reaches your screen.
That is what this cluster is about: the cognitive grain you are designing along, or against. Work with it and an interface feels obvious - people just know what to do. Ignore it and they bounce off perfectly logical screens for reasons they could never quite put into words.
Each entry below makes the idea happen to you first - your own attention wandering, your own memory quietly filling a gap, your own reach for the obvious control - then explains what you just felt and what it means back at the drawing board.
The cognitive psychology entries 16
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cognitive psychology
Cognitive load
The mental effort required to complete a task. Too much and people slow down, make mistakes, or quit.
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cognitive psychology
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.
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cognitive psychology
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.
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cognitive psychology
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.
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cognitive psychology
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.
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cognitive psychology
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.
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cognitive psychology
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.
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cognitive psychology
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.
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cognitive psychology
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.
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cognitive psychology
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.
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cognitive psychology
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.
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cognitive psychology
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.
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cognitive psychology
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.
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cognitive psychology
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.
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cognitive psychology
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?".
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cognitive psychology
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.
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Know these already? Take the cognitive psychology quiz, or revise the terms with flashcards.