UX glossary: every UX term, defined and demonstrated

A

A/B testing research methods: A/B testing shows two versions of something to two random groups and compares a metric - clicks, sign-ups, sales - to see which performs better. Done right it settles design arguments with evidence; done hastily it manufactures false winners from noise.
Accessible forms (labels and instructions) accessibility: An accessible form gives every control a real, programmatically-associated label and clear instructions, so a screen-reader user hears what each field is for before they fill it in. Without that, the form may look fine but announces as a row of nameless "edit text" boxes - usable by sight, a guessing game by ear.
Accordion ui patterns: An accordion is a stack of headed panels that open and close on click, folding long content into a scannable list of titles you can expand as needed. This very demo is one - the panels below are the pattern.
Aesthetic-usability effect laws & principles: The aesthetic-usability effect is our habit of judging better-looking things as easier to use - whether or not they actually are. Polish buys a benefit of the doubt, smoothing over small frictions and making people more forgiving.
Affordance interaction design: An affordance is a visual cue showing what action you can take - like a raised button suggesting 'press me' or underlined blue text implying 'click me'. Clear cues guide users; unclear or misleading ones leave them guessing.
Affordance vs signifier interaction design: An affordance is what an element lets you do - a button can be pressed, a slider can be dragged. A signifier is the cue that tells you so - the shadow, the label, the cursor change. The affordance is the possibility; the signifier is the advertisement for it.
Alignment visual design: Alignment is lining elements up to shared edges and a common grid, so the eye reads invisible straight lines connecting them. It is the cheapest way to make a layout feel considered - and its absence is the first thing that reads as amateur.
Alt text accessibility: Alt text is the written description an image carries for people who can't see it - read aloud by a screen reader, and shown if the image fails to load. Good alt conveys what the image means; bad or missing alt leaves a hole in the page.
Anchoring persuasion: Anchoring is the way the first number you see sets the frame for every judgement after it. Show a high price first and the real one feels like a bargain - not because it changed, but because you now have something to measure it against.
ARIA accessibility: ARIA (Accessible Rich Internet Applications) is a set of HTML attributes - roles, states and properties - that tell assistive technology what a custom element is and what it's doing when native HTML can't. It adds an accessibility layer on top of the markup: this div is a switch, it's currently on, this region is live. Powerful, and easy to get wrong.
Authority persuasion: Authority is our tendency to trust, and act on, advice that comes from a credible source - an expert, a credential, an official badge. The same claim lands harder when it arrives with a reason to believe the person making it.

B

Bait and switch design ethics: Bait and switch is advertising one thing and delivering another - a button that promises a free download and hands you a sign-up wall instead. The bait gets the click; the switch is what actually happens.
Bounce rate metrics: Bounce rate is the share of visits where someone lands on a page and leaves without any further interaction - one page, no second click. It's easy to measure and easy to misread: a high bounce rate can mean people couldn't find what they wanted, or that they found it instantly and left satisfied. The number means nothing until you know what the page was for.
Breadcrumbs ui patterns: Breadcrumbs are the small trail of links - Home > Catalogue > Shoes - that shows where the current page sits in the hierarchy and lets you step back up it. They answer two quiet questions at once: where am I, and how do I get back?

C

Captions, transcripts and audio descriptions accessibility: These are three ways to make audio-visual content reach people who can't fully see or hear it. Captions put the audio (speech and meaningful sounds) on screen, in sync, for people who can't hear. A transcript is the whole thing as readable text. Audio description narrates the important visuals, in the gaps, for people who can't see. Each serves a different barrier - and most media needs more than one.
Card sorting research methods: Card sorting is a research method where users group labelled cards into categories that feel natural to them. It shows how they mentally organise information - the raw material for an information architecture built on their logic, not yours.
Cards ui patterns: A card is a container that groups everything about one thing - image, title, detail, action - into a single bounded unit you can scan and act on as a whole. Its job is to make the edges of "one item" obvious, so a list of many things reads as many things, not one undifferentiated run of text.
Change blindness cognitive psychology: 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.
Choice overload cognitive psychology: 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.
Chunking cognitive psychology: 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.
Cognitive accessibility accessibility: Cognitive accessibility is designing so people with differences in memory, attention, language, literacy or processing - whether a permanent condition, a temporary state like stress or fatigue, or just being new - can understand and use a product. It's less about a single assistive technology and more about reducing the mental effort an interface demands.
Cognitive load cognitive psychology: The mental effort required to complete a task. Too much and people slow down, make mistakes, or quit.
Colour blindness accessibility: Colour blindness is reduced ability to tell certain colours apart - most commonly red from green - affecting a meaningful slice of people, mostly men. For design it means one thing above all: if colour is the only way you signal something, a lot of users simply won't receive the message.
Colour contrast visual design: Colour contrast is the measurable difference in relative luminance between text and its background, expressed as a ratio from 1:1 to 21:1. It determines whether words are comfortable to read or quietly exclude people.
Colour schemes visual design: A colour scheme is a set of hues chosen by their positions on the colour wheel so they work together. The common recipes - complementary (opposite), analogous (neighbouring), triadic (evenly spaced) - are just rules for picking angles, giving you palettes that feel harmonious instead of arbitrary, from one base colour.
Commitment and consistency persuasion: People feel a strong pull to act in line with what they've already said or done. So a small, early commitment - a tick, a tiny first step, a stated preference - makes a larger, consistent request far easier to agree to later. It's the "foot in the door": the first small yes paves the way for the bigger one.
Confirmation bias cognitive psychology: 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?".
Confirmation dialog interaction design: A confirmation dialog interrupts before a consequential action to make you stop and agree. Done well, it states exactly what will happen and offers a specific, labelled choice, so the decision is informed. Done badly - a vague "Are you sure? OK / Cancel" on everything - it's noise people learn to dismiss, training the very carelessness it was meant to prevent.
Confirmshaming design ethics: Confirmshaming is wording the opt-out to make declining feel foolish, guilty, or cheap - 'No thanks, I'd rather pay full price.' The choice remains; the shame is the thumb on the scale.
Conversion rate metrics: Conversion rate is the share of people who complete a goal - buy, sign up, subscribe - out of everyone who could have. It's usually quoted end to end, but it's really the product of every step's survival rate along the way.
CSAT (customer satisfaction score) metrics: CSAT - customer satisfaction score - asks people to rate their satisfaction, usually on a short scale, right after an experience, and reports the percentage who answered positively (typically the top one or two ratings). It's a quick, intuitive read on "did that go well?" for a specific interaction - a purchase, a support chat, a feature.
Customer effort score (CES) metrics: Customer effort score (CES) asks one thing after an interaction: how easy was it to get what you needed? Usually a single agree-scale statement ("the company made it easy to handle my issue"), it shifts the question from "are you delighted?" to "did we get out of your way?" - on the theory that reducing effort keeps people more reliably than trying to wow them.

D

Dark patterns design ethics: Interface tricks that nudge you toward choices you didn’t intend to make - for the business’s benefit, not yours.
Decoy effect persuasion: The decoy effect happens when adding a third, intentionally worse option shifts your choice between the other two. The decoy isn’t meant to be selected - it’s there to make one of its neighbours seem like the better deal.
Defaults interaction design: A default is the choice already made for you - the value a field starts with, the box that's pre-ticked, the option selected before you touch anything. Because most people never change them, defaults quietly decide the outcome for the majority, which makes choosing them one of the most powerful - and most ethically loaded - decisions in an interface.
Design system process & strategy: A design system is the single source of truth for an interface: the design tokens, reusable components and written guidelines that let many people build a consistent product quickly. Define something once, use it everywhere, change it in one place.
Design thinking process & strategy: Design thinking is a human-centred way to tackle messy problems: understand real people, sharply define their problem, generate lots of ideas, build rough prototypes and test them - looping back as you learn. The point is to start from the human, not the solution.
Design tokens process & strategy: Design tokens are named values for the small decisions a design repeats - colours, spacing, corner radius, type sizes - stored once and referenced everywhere. Change the token and everything built from it changes at once.
Discoverability interaction design: Discoverability is whether people can find out what an interface can do, and how to do it, just by looking and trying - without a manual, a tooltip or a tip-of-the-day. A feature that exists but can't be found doesn't really exist for most users; the function is only as useful as it is visible.
Doherty threshold interaction design: The Doherty threshold is the point - around 400 milliseconds - where a system’s response feels immediate and keeps you in flow. Beyond that, attention fades: people hesitate, re-check, and disengage, even when the result is the same.
Double diamond process & strategy: The double diamond model shows design as two diamonds: the first explores then defines the right problem, the second explores then delivers the right solution. Each diamond opens wide before narrowing to a point.
Drip pricing design ethics: Drip pricing advertises a low headline price, then reveals mandatory fees one at a time as you move through checkout - a booking fee here, a service charge there - so the real total only appears at the very end, when you're least likely to leave.
Dunning-Kruger effect cognitive psychology: 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.

E

Empty state ui patterns: An empty state is what a screen shows when there is nothing to show yet - no results, no items, no history. It is the most overlooked screen in the product, and often the first one a new user meets.
Error prevention interaction design: Error prevention is designing so a mistake can't happen in the first place - constraints, sensible defaults, disabling impossible actions, formats that can't be entered wrong - rather than letting the slip occur and catching it with a message afterwards. The best error is the one the interface made impossible to make.
Error rate metrics: Error rate is how often people make errors while doing a task - mistakes per attempt, or the share of attempts that go wrong. It's a usability metric, not a verdict on users: a high error rate almost always points at a confusing design, not careless people, and the type of error tells you what kind of fix it needs.
Error recovery and undo interaction design: Error recovery is what an interface offers after a mistake: a way back. The strongest form is undo - the action happens immediately, with an easy reversal sitting right there - which lets people move fast without fear, because anything done can be undone. It treats slips as normal and recoverable, not as things to interrogate up front.

F

Fake scarcity design ethics: Fake scarcity is a made-up shortage - "only 2 left!", "low stock!" - shown to pressure you into buying, when the number reflects nothing real and never actually runs out. It borrows the genuine urgency of true scarcity but lies about the facts, so the pressure is manufactured rather than honest.
Fake social proof design ethics: Fake social proof is invented evidence that other people are buying, watching or endorsing something - "37 people are viewing this right now", fabricated reviews, a fake "just purchased" popup - manufactured to borrow the persuasive weight of the crowd when no real crowd exists. It counterfeits the genuine signal that real social proof carries.
Fake urgency design ethics: Fake urgency is a deadline that isn't real - a countdown timer that resets when you reload, an "offer ends today" that's there every day - shown to rush you into deciding before you've thought it through. It mimics a genuine time limit but is attached to nothing, so the pressure is pure theatre.
Feedback interaction design: Feedback is the interface answering back: a clear sign of what just happened and what to do next. Act without it and people are left guessing whether anything worked at all.
Figure-ground visual design: Figure-ground is how our eyes distinguish what’s in front (the figure) from what’s behind (the ground). Interfaces use it constantly - a dialog must appear on top of the page, not blend into it.
First-click testing research methods: First-click testing asks one simple question: where do users go first to complete a task? That first click matters more than any other - get it right and the task usually follows; get it wrong and it rarely recovers.
Fitts's law interaction design: The time it takes to hit a target grows as it gets smaller or farther away. Large, nearby targets are fast to hit; small, distant ones take longer.
Five-second test research methods: Show a design for five seconds, then ask what they remember. What sticks is what the layout really shouts - and what it quietly hides.
Five-second test vs first-click test research methods: Two fast, low-cost tests that answer different questions. The five-second test flashes a screen briefly and asks what people remember - does it communicate? The first-click test asks where they’d click to complete a task and observes - can they find the way? Impression versus action.
Focus management accessibility: Focus management means deliberately guiding where keyboard focus lands as the interface updates - moving it into a dialog when it opens, returning it to the trigger when it closes, or placing it on a new view or error. Done right, keyboard and screen-reader users stay in a sensible place; done wrong, they’re left stranded - either on invisible elements or back at the top after every action.
Focus order accessibility: Focus order is the sequence the Tab key follows across a page. When it matches visual order, navigation feels natural; when it doesn’t, each tab can jump unexpectedly.
Forced continuity design ethics: Forced continuity is a free trial that converts to a paid subscription without clear warning - the card is charged upfront, and payment triggers instantly when the trial ends. The trial was real; the trick is the silence around the charge.
Framing effect persuasion: The framing effect is how the same fact, described positively or negatively, lands differently - "90% fat-free" feels healthier than "10% fat" though they are the identical tub. We react to the spin as much as to the substance.
Friction interaction design: Friction is any effort an interface puts between a person and what they're trying to do - a step, a confirmation, a wait, a decision. It isn't simply bad: friction on the wrong action repels people, but a deliberate dose on a risky one is a safety net. The skill is matching the friction to the stakes, not removing it everywhere.

G

Gestalt: closure laws & principles: Closure is the mind’s tendency to fill in gaps and complete shapes from incomplete visual cues - perceiving a whole circle, triangle, or icon even when only fragments are shown.
Gestalt: common region laws & principles: Common region is the grouping effect that occurs when items share a boundary: surround some elements with a line or tinted background, and they’ll be perceived as a group - even if other items are closer or equally nearby. It’s one of the strongest grouping cues, alongside visible connections, and typically overrides proximity and similarity.
Gestalt: continuity laws & principles: Continuity is the eye's natural tendency to follow smooth, unbroken paths. When lines or rows of elements intersect or branch, you group those that continue in the same direction, not those that merely connect.
Gestalt: prägnanz laws & principles: Prägnanz - the law of good figure - means the mind naturally prefers the simplest, most stable interpretation of what it sees. When faced with ambiguity, you perceive the cleanest version: a few whole shapes rather than many odd ones. You can see this principle in action on this page.
Gestalt: proximity laws & principles: Things close together are seen as a group; things spaced apart are seen as separate. Proximity is one of the strongest cues for grouping - it usually overrides shape or colour, though a shared boundary or visible connection can override it.
Gestalt: proximity vs common region laws & principles: Both group separate items, but in different ways. Proximity groups by closeness - things near each other belong together. Common region groups by shared space - items within one boundary belong together, even if something closer lies outside. When they conflict, the boundary usually takes precedence.
Gestalt: similarity laws & principles: The Gestalt law of similarity tells us we mentally group items that share visual traits - like colour, shape, or size - and perceive them as belonging together, even when spaced apart. Similarity alone suggests they form a set.
Gestalt: uniform connectedness laws & principles: Uniform connectedness is among the strongest Gestalt grouping cues: elements joined by a line, or enclosed together, are seen as one group - even when they sit far apart or look nothing alike. A visible connection generally beats proximity and similarity, acting at least as strongly as a shared region.
Goal-gradient effect persuasion: The goal-gradient effect is the way motivation rises as you near a reward - you push harder close to the finish line than at the start. Show visible progress, and even a small head start makes the goal feel reachable, so people keep going.

H

HEART framework metrics: HEART is Google's framework for measuring user experience across five dimensions - Happiness, Engagement, Adoption, Retention and Task success - so you capture quality of experience, not just business output. Its real engine is the "Goals-Signals-Metrics" process that turns each fuzzy dimension into a concrete number, forcing you to decide what success means before you pick what to count.
Heuristic evaluation research methods: A quick expert review that checks an interface against a short set of usability rules - you can see this in action right here.
Hick's law cognitive psychology: The more choices you offer, the longer a decision takes - and the cost grows logarithmically, not linearly. Choices take time, not just space.
Hick's law vs Miller's law cognitive psychology: 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.

I

Information architecture process & strategy: Information architecture is how a product’s content is organised, labelled and connected so people can find things and know where they are. It’s the floor plan beneath the interface - invisible when it works, maddening when it doesn’t.
Interactive states (hover, focus, active) interaction design: Every interactive element lives in several states - default, hover, focus, active, disabled - and each is a piece of feedback. They tell people what's interactive, where they are, and that the thing heard them. Designing only the default state leaves an interface that looks dead, loses keyboard users, and never confirms a tap.

J

Jakob's law laws & principles: People spend most of their time on other sites, so they expect yours to work like those. Familiar patterns are quicker to use because users already know them - you’re reusing the habits the web has taught them.
Jobs to be done process & strategy: Jobs to be done is the idea that people don't want your product, they want the progress it gives them - they "hire" it to do a job. Focus on the job, not the feature or the demographic, and you design for what people are actually trying to achieve.

K

Keyboard navigation accessibility: Keyboard navigation means using the keyboard to operate an interface: Tab to move between controls, arrow keys to navigate within a group, Enter or Space to activate. If the mouse disappeared, everything would still have to work.
Keyboard trap accessibility: A keyboard trap is when focus enters a spot but can't exit via keyboard - a widget, embed or dialog that captures Tab, leaving keyboard or switch users stranded and unable to reach the rest of the page. For someone who can't use a mouse, it’s not an annoyance; it’s a dead end that can make the whole page unusable.

L

Leading questions research methods: A question worded so it nudges you toward a particular answer - through a loaded word, a built-in assumption, or a scale that only points one way. It measures the wording, not the truth.
Liking persuasion: Liking is the simplest of Cialdini's principles: we say yes more readily to people and brands we like. Similarity, genuine compliments, cooperation toward a shared goal, familiarity and warmth all raise liking - and liking, in turn, lowers resistance to a request. We agree with those we feel good about.
Loss aversion persuasion: Loss aversion is the way losing something hurts more than gaining the same thing pleases - roughly twice as much. The maths is identical; the feeling is not, which is why "don't lose this" pulls harder than "get this".

M

Mental model cognitive psychology: 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.
Microcopy interaction design: The small words inside an interface - button labels, hints, placeholders, error messages - that quietly guide, reassure and give it a voice. Tiny by word count, decisive by impact.
Microinteractions interaction design: A microinteraction is a single small moment built around one task - a toggle flipping, a like animating, a field confirming it saved. Each is tiny, but they're where an interface answers "did that work?" in the instant after you act, and where a product feels responsive and considered rather than dead and uncertain.
Miller's law cognitive psychology: 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.
Modal dialog ui patterns: A modal dialog overlays the page and requires a decision before you can proceed - everything behind it is disabled. Used well, it focuses attention; used poorly, it traps the keyboard and loses users entirely.
Modal vs toast ui patterns: Two ways to communicate that something has happened. A modal halts activity and requires a response before proceeding; a toast appears briefly, delivers its message, then disappears. One interrupts, one glides away - and choosing the wrong one creates a usability issue.

N

Net promoter score metrics: Net promoter score asks one question - "how likely are you to recommend us?" on a 0 to 10 scale - then subtracts the share of detractors (0 to 6) from the share of promoters (9 to 10). The 7s and 8s sit in the middle as a neutral zero. The result runs from -100 to +100.
Nielsen's 10 usability heuristics research methods: Nielsen's 10 usability heuristics are ten rules of thumb for spotting interface problems - keep users informed, speak their language, prevent errors, and so on. They are the checklist behind a heuristic evaluation, and the most widely used yardstick in usability.

O

Occam's razor laws & principles: Occam's razor: among designs that solve the problem, the simplest one wins. Don't add elements - options, steps, decoration - beyond what the job needs; every extra is one more thing to read, maintain and get wrong.
Optimistic UI interaction design: Optimistic UI updates the screen the instant you act - as if the action had already succeeded - and quietly confirms with the server in the background. It bets that the request will work (it nearly always does), so the interface feels immediate instead of making you watch a spinner wait on the network.

P

Pagination vs infinite scroll ui patterns: Two ways to handle a long list: pagination splits it into numbered pages you navigate between, while infinite scroll loads more content as you scroll down. Pagination gives users control and lets them know where they are; infinite scroll offers a smooth, continuous flow without a clear end.
Pareto principle laws & principles: The Pareto principle shows that most impact comes from a small part of the cause - about 80% of value from 20% of the things. In products, a few features drive most use.
Parkinson's law laws & principles: Parkinson's law: work expands to fill the time given. Give it a week and it takes a week; give it an afternoon and it’s done by tea - often just as well.
Peak-end rule cognitive psychology: 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.
Postel's law laws & principles: Postel's law - the robustness principle - says be conservative in what you send and liberal in what you accept. Take input in whatever shape people naturally give it, then tidy it up yourself, instead of rejecting anything that isn't already perfectly formatted.
Preselection design ethics: Preselection is choosing for the user in your own favour and hoping they don't notice - a pre-ticked opt-in, an extra already in the basket, the pricier plan selected by default. It weaponises the same inertia that makes good defaults helpful, but points it at the business's interest instead of the user's.
Privacy zuckering design ethics: Privacy zuckering tricks users into sharing more than they intend by defaulting settings to 'share', hiding private options behind confusing language and extra clicks. Named after a certain founder, it assumes consent without ever asking for it.
Progressive disclosure interaction design: Show people just what they need right now, and tuck the rest behind a clear next step. It keeps the first view simple without hiding anything permanently.

R

Readability and plain language accessibility: Readability is how easily text can be read and understood; plain language is writing deliberately for that ease - common words, short sentences, active voice, no needless jargon. It isn't dumbing down; it's respecting the reader's time and the fact that stress, distraction, a second language or a cognitive difference all lower the reading level anyone can comfortably handle.
Reciprocity persuasion: Reciprocity is the pull to return a favour - give someone something first and they feel quietly obliged to give back. Lead with genuine value and a later ask lands softly; open with the ask and it reads as a demand.
Recognition vs recall cognitive psychology: 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.
Reduced motion accessibility: Reduced motion is honouring a user's request to cut animation. Movement on screen makes some people dizzy, nauseous or worse; the prefers-reduced-motion setting is them asking you to keep things still, and a good interface listens.
Roach motel design ethics: A roach motel is a flow that’s easy to join but deliberately hard to leave - one click to subscribe, a hidden maze to cancel. The asymmetry is the trick: friction only ever runs one way.

S

Scarcity persuasion: Scarcity creates pull by making something feel more valuable when it seems rare or about to run out - like 'only 2 left' or 'offer ends in 5:00'. It works because the sting of losing an option outweighs the pleasure of gaining one.
Screen readers accessibility: A screen reader is software that speaks (or sends to a braille display) what's on screen, letting blind and low-vision people use a computer by ear. Crucially, it turns a two-dimensional visual layout into a one-dimensional stream - read in source order, element by element - so the experience is linear, sequential, and entirely dependent on the meaning in your markup.
Selective attention cognitive psychology: 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.
Semantic HTML accessibility: Semantic HTML means using elements for what they mean - header, nav, main, button, h1-h6, list - rather than wrapping everything in styled divs and spans. The meaning is invisible on screen but everything to assistive technology: it's what lets a screen reader announce roles, list headings, and jump straight to the main content.
Serial position effect cognitive psychology: 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.
Skeleton screen ui patterns: A skeleton screen is a placeholder that shows the shape of content while it loads - grey blocks where text and images will appear - instead of a spinner or blank. It makes the same wait feel shorter by showing progress toward something specific.
Skeuomorphism interaction design: Skeuomorphism is design that imitates real-world objects - the leather-stitched diary, the felt poker table, the push-button with a bevel and a shadow. Its purpose was never decoration for its own sake: by borrowing the look of physical things, it borrows their affordances, so a control looks pressable, draggable or turnable before anyone explains it.
Skip links accessibility: A skip link is a hidden link, revealed the moment you press Tab, that jumps straight past a repeated block - usually the navigation - to the main content. Sighted mouse users never see it; keyboard users would be lost without it.
Social proof persuasion: People look to what others do to decide what is right, especially when they are unsure. In an interface, that means showing real evidence that real people use, rate and trust the thing.
Social proof vs authority persuasion: Two routes to "you can trust this". Social proof points sideways - lots of people like you chose this. Authority points up - an expert or credential vouches for it. The crowd versus the expert; both borrow credibility, from very different places.
Sunk cost fallacy persuasion: The sunk cost fallacy is letting money, time or effort you have already spent - and cannot get back - keep you committed to something that is no longer worth it. The only sound question is what the next step is worth; the fallacy answers a different one - what you would be "wasting" by stopping.
Sunk cost fallacy vs loss aversion persuasion: Loss aversion is the tendency for losses to feel worse than equivalent gains feel good. The sunk cost fallacy is one error that this bias can lead you into: continuing with something just because quitting would mean acknowledging what you’ve already spent is gone. One is the bias; the other is the mistake it can cause.
System usability scale metrics: The system usability scale is a short questionnaire with ten statements rated from strongly disagree to strongly agree. It converts how usable something feels into a single score from 0 to 100. It’s quick, standardised, and surprisingly comparable across very different products.

T

Tabs ui patterns: Tabs slice one area of the screen into parallel panels and show just one at a time. They keep a page short by hiding all but the panel you've picked - which is the whole trick, and the whole risk.
Tabs vs accordion ui patterns: Both hide content behind clickable labels, but tabs display them side by side horizontally, revealing one at a time, while accordions stack them vertically and let panels expand in place. The choice often depends on how many sections there are and screen width.
Target size accessibility: Target size is the size of a tappable or clickable element plus the space around it. If it’s too small or too crowded, users may miss it - due to fat fingers, tremors, small screens, or a moving bus - and a control they can’t reliably hit is effectively broken.
Task success rate metrics: Task success rate is the share of people who finish a task - four of five users complete it, so 80%. It is the most basic measure of whether a thing works at all, and the easiest to read too much into.
Tesler's law laws & principles: Every process has a minimum complexity that can't be eliminated - only moved. The real question isn't whether to remove it, but who carries it: the user or the team building it. You can see this in action on this page.
Thumb zone interaction design: The thumb zone is the area of a phone screen a person can comfortably reach with the thumb of the hand that's holding it - roughly the lower and centre of the display. The far corners, especially the top, are a stretch or need a second hand. Put the things people tap most inside the easy zone, and keep the awkward corners for the rare and the harmless.
Time on task metrics: Time on task is how long it takes someone to complete a specific task, from start to finish. It's the most common efficiency metric in usability testing - and one of the easiest to misread.
Toast notification ui patterns: A toast is a small, transient message that slides in to confirm an action - "Saved", "Archived", "Link copied" - then disappears on its own. It gives lightweight feedback without interrupting, the opposite of a modal you must dismiss.
Tooltips interaction design: A tooltip is a small label that appears on hover or focus to explain a control - most often a bare icon whose meaning isn't obvious. Used well it's a quiet safety net for recognition; used as a crutch it hides essential information behind an interaction many people can't or won't perform.
Typography hierarchy visual design: Typographic hierarchy is using size, weight, spacing and colour to rank text, so the eye knows what to read first, what's a heading, what's an aside. It is visual hierarchy done with type alone - the structure you feel before you read a word.

U

Unity persuasion: Unity is the pull of shared identity - we're more readily persuaded by people we count as one of us. Not just "people like me do this" (that's social proof) but "we are the same kind of person", a family, a profession, a tribe.
Usability testing research methods: Watching real people attempt real tasks with your design, to find where it trips them up. It is not asking whether they like it - it is handing them something to do and seeing what actually happens.
Usability testing vs heuristic evaluation research methods: Two ways to spot usability problems. Usability testing watches real people trying tasks to see what actually trips them up. Heuristic evaluation has experts review the interface against known principles. One shows what happens in reality; the other predicts it - and they uncover strikingly different issues.
User journey map process & strategy: A user journey map lays out the steps someone takes to reach a goal and plots how they feel at each one. The feeling is the point: it turns a flat list of stages into a curve where the low spots - the moments worth fixing - stand out.
User persona process & strategy: A user persona is a short, research-based profile of a representative user - their goals, context, and frustrations - given a name and a face. It turns the vague, shifting idea of 'the user' into one specific person you can design for.
UX vs UI process & strategy: UI is the surface - the visible, interactive layer you see and touch: colours, type, buttons, layout. UX is the entire experience of using the thing, including screens and everything around them: finding it, the flow, the wait, the recovery when it goes wrong. UI is part of UX, not a synonym for it.

V

Visual hierarchy visual design: The order your eye follows across a layout, shaped by size, weight, colour and space. It tells you what grabs attention first - and what slips by.
Von Restorff effect cognitive psychology: 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.

W

WCAG levels (A, AA, AAA) accessibility: WCAG - the Web Content Accessibility Guidelines - groups its success criteria into three conformance levels: A (the bare minimum), AA (the standard most organisations and laws target), and AAA (the highest, often impractical to meet site-wide). Each level builds on the last, so AA includes all of A, and AAA includes all of AA.
Whitespace visual design: Whitespace (or negative space) is the empty area between and around elements. It is not wasted room: it groups what belongs together, guides the eye, and makes a layout legible.

Z

Zeigarnik effect cognitive psychology: 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.

The UX glossary

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

R

S

T

U

V

W

Z

Now make them stick