The psychology behind every teardown. The idea first, then the critter acting it out.
The critter walks into a café with a menu of forty drinks, reads it twice, and orders the same latte as always.
More options leads to harder decisions
Every extra option adds a little to the time someone needs before they pick. A short menu gets a quick answer, while a long one makes people stop and weigh each item. More to choose from means more effort and a slower decision.
The critter has decided its new plant is thriving, so it counts the one new leaf and doesn't look at the three brown ones.
People look for evidence that confirms what they think
Once people believe something, they go looking for evidence that backs it up. They also read unclear facts in its favour, like the supporting ones better, and remember them longer than the ones that cut against what they already think.
The critter walks past a bakery on the way to the shop and somehow comes home with bread it never planned to buy.
Previous stimuli influence users' decision
A small hint, a picture or a word, can bring certain things to mind and change how someone reacts next. It works because what people just saw or heard is still switched on in short-term memory when the next prompt or task arrives.
The critter tries to follow a recipe, answer a text and keep an eye on the pasta at once, and the pasta boils over.
Total amount of mental effort that is required to complete a task
Cognitive load is how much thinking a task asks of someone. Picture it as the brainpower a person has to spend to use a product. When a screen asks for more processing than people can manage, the load is too heavy and they struggle.
Seen in: Skreno, slide 7, pushr, slide 1, Hemory, slide 6
The first jacket the critter sees costs $400, so the $150 one next to it suddenly feels like a bargain.
Users rely heavily on the first piece of information they see
The first number or fact people see becomes a reference point for every judgement after it. It pulls on their choice even when it has nothing to do with the decision. That makes it a handy way to make something seem worth more.
The office puts the fruit bowl by the door and the biscuits on a high shelf, and the critter starts grabbing apples without thinking about it.
Subtle hints can affect users' decisions
Many choices are made without much conscious thought. A small cue or a change in setting can steer people towards one option while leaving them free to pick another. Common tools are priming, defaults, making one option stand out, and how varied the options seem.
Seen in: pushr, slide 9
The critter's new camera opens in auto mode; the manual dials only show up once it goes looking for them.
Users are less overwhelmed if they're exposed to complex features later
A product is easier to use when advanced features show up later instead of all at once. At the start, show newcomers only the core of the product, then reveal more options as they find their feet. Beginners get a simple screen, and experienced people still get the power they need.
Seen in: Articos, slide 3, Skreno, slide 9
The critter can hit the big lift button with its elbow while carrying shopping, but not the tiny 'door open' one.
Large and close elements are easier to interact with
Fitts's law predicts how long it takes to reach a target from how far away it is and how big it is. Closer, bigger targets are quicker to hit. It mostly describes pointing, whether with a hand in the real world or with a mouse on a screen.
Seen in: Skreno, slide 6
The critter has walked past the same poster at the bus stop for a month and couldn't tell you what it's for.
Users tune out the stuff they get repeatedly exposed to
People have learned to skip over anything that looks like an ad. They also skip what sits next to ads, and whatever appears in the spots where ads usually go.
Popcorn costs $4 small or $8 large, until a $7.50 medium appears, and now the critter happily pays $8 for the large.
Create a new option that's easy to discard
Add a third option that is plainly worse than one of the first two, and people see those two differently. The decoy loses to one of them (the target) on every point, but to the other (the competitor) on only some, so the target starts to look like the obvious pick. That lopsided match-up is why it's also known as the asymmetric dominance effect.
'90% fat free' sounds healthier to the critter than '10% fat', though the yoghurt is the same.
The way information is presented affects how users make decisions
The way information is put, its wording and presentation, can sway a decision more than the facts themselves. Part of the reason is that people weigh losses and gains unevenly. Daniel Kahneman and Amos Tversky described this in their prospect theory; see also Loss Aversion.
Seen in: bonds, slide 8
The critter is thinking about buying a red car, and suddenly there are red cars on every street.
Users' thoughts filter what they pay attention to
Whatever is already on someone's mind decides what they spot. A person worried about money notices every price, and a hungry one notices every advert for food. On a screen, users hunt for what matches their current goal or worry and overlook the rest, even when it's important.
Full after lunch, the critter swears it'll skip snacks tonight; at 10 pm it's in the kitchen.
People underestimate how much emotions influence user behaviors
In a calm moment, people misjudge how they'll behave when worn out, angry, afraid or in a hurry, and the reverse holds too. Product teams work in quiet offices, yet their users may be stressed, short of time or on a weak signal. Try the journey under the conditions people will actually face.
Seen in: Pip, slide 8, Hemory, slide 8, CraveLens, slide 8
On a busy shop front, the critter's eye goes straight to the big red SALE sign, then to whatever sits next to it.
Elements used to guide users' eyes
Certain elements catch attention before anything else and offer a starting point: a large headline, an image, a bright button or a face. Used with care, they guide a visitor's gaze across the page in the sequence you planned. Add too many and the eye can't settle anywhere.
In a row of grey suitcases on the airport belt, the critter spots its bright yellow one at once.
People notice items that stand out more
Also known as the isolation effect: among a group of similar items, the odd one out is what people notice and recall. Make the main action look unlike everything near it. Do it for one thing at a time, though, because when everything shouts, nothing gets heard.
Seen in: pushr, slide 5
The critter reads a newspaper: big headline first, then the photo, then maybe the first paragraph, and that's it.
The order in which people perceive what they see
A page's order of importance comes from size, colour, contrast, position and the space around things. These tell people where to look first, what comes next and what can wait. With a clear order, users get the page at a glance; when everything has the same weight, they must read it all to find what they wanted.
Busy counting its change at the till, the critter never notices the cashier has a new haircut.
People filter out things from their environment when in focus
People busy with a task tune out whatever doesn't seem part of it, even large, obvious things. A message that appears while users are focused elsewhere may never be noticed. Show information where their eyes and minds already are.
The critter hears that three famous founders dropped out of university and wonders if it should too, without hearing about the thousands for whom it went badly.
People neglect things that don't make it past a selection process
People judge from the cases that made it and overlook those that failed, which makes success seem likelier and easier to repeat than it really is. In products, that means learning only from the users who stayed. Those who left, and their reasons, often have more to teach.
The critter sees two shoes side by side in a window and assumes they're a pair, though they're two different models.
Elements that are close and similar are perceived as a single unit
Elements that sit near each other and look alike are read as one group with one meaning. Putting things side by side also asks people to compare them, like two prices, two plans or a before and after.
The critter pushes a door with a big handle on it. It was a pull door; the handle said 'pull' to everyone but the sign.
Elements that communicate what they will do
A signifier is a hint about what something is for and how it works, like a button that looks raised, an underlined link or a handle on a door. If the hint is missing or misleading, people push doors meant to be pulled and tap words that aren't links.
Seen in: GenPage, slide 8, Siteprint, slide 8
On a white wall covered in pale notes, the critter only reads the one written in thick black marker.
Users' attention is drawn to higher visual weights
Eyes go to whatever carries the most weight on the screen: the darkest, brightest, largest or most unusual thing. High contrast makes the key element obvious and keeps text easy to read. Low contrast hides both.
The critter's phone buzzes, 'Your parcel is at the door', and it goes straight to the door.
When the information on what to do next is within the prompt itself
External triggers are prompts that come from outside the person, such as an email, a notification, a sign or a button, and each carries the next step with it. The good ones spell out the action and put it a single tap away. Overdo them and people stop paying attention.
Seen in: pushr, slide 8
Three coffee sizes on the board, and the critter orders the medium without really thinking about it.
People tend to choose the middle option in a set of items
Shown a row of options, people lean towards the middle one, treating it as the safe or popular choice, or the best one. Pricing pages often use this, putting the plan they most want to sell in the centre column.
In the supermarket, the critter assumes the price tag under the apples is for the apples, but it's for the pears beside them.
Elements close to each other are usually considered related
Items that sit near each other look like they belong together, and items set apart look separate. Spacing alone does much of the grouping. A label that sits far from its input box, or crowds the next one, gets paired with the wrong field.
Seen in: Tiny Little Office, slide 8
The critter's 'simple' new remote has only three buttons, so changing the input means holding two of them down for five seconds.
If you simplify too much, you'll transfer some complexity to the users
Tesler's law of conservation of complexity says every task holds a core of complexity that can be moved around but never removed. If the product doesn't absorb it, the user has to. Strip a screen down too far and people must handle the tricky bits themselves.
Seen in: Givingli, slide 8, Siteprint, slide 4, Hemory, slide 5
The critter won't 'go for a run', but it will 'just put its shoes on', and then it's out the door.
Users are more likely to take action when the effort is small
People are more likely to begin when the opening step is tiny and quick. Cut the first action down to one tap, one question or one minute, and more people start. Having started, they tend to keep going.
The critter presses the lift button; it doesn't light up, so it presses it five more times.
When users take action, feedback communicates what happened
When people act, they need a sign that it worked, like a sound, a tick or a change on screen. Without one, they try again, get anxious or quit. Good feedback shows people how the product responds to them.
Seen in: Skreno, slide 4, Tiny Little Office, slide 7
Told the wine is expensive, the critter finds it delicious. It's the same wine as last week.
People tend to be influenced by their own expectations
People tend to see what they expect to see. Expect something good and they spot the good parts, and expecting bad works the same way. Reviews, branding and first looks plant those expectations long before the first click.
The critter buys the beautiful kettle; it drips when it pours, but the critter says it doesn't mind.
People perceive designs with great aesthetics as easier to use
People assume attractive designs work better, and they're quicker to forgive small flaws in them. Good looks buy patience, but in testing they can also mask real usability problems.
Seen in: Tiny Little Office, slide 3
Two restaurants side by side: one empty, one with a queue. The critter joins the queue.
Users adapt their behaviors based on what others do
When people aren't sure what to do, they copy what others around them are doing and assume it must be right. The less clear the situation, the stronger that pull. Numbers matter too: the bigger the crowd, the safer the choice looks.
Seen in: Givingli, slide 1
'Only 2 left in your size', and the critter, who was just browsing, buys the shoes.
People value things more when they're in limited supply
Scarcity is mostly used to push people to buy, but it can also lift quality by making people think harder before they act. It comes in a few forms: limited time, limited quantity or limited access. Never fake it, or people will push back (see Reactance).
The episode ends on a cliffhanger and the critter presses 'next episode' at 1 am.
Users have a desire to seek out missing information
The curiosity gap is the distance from what people know now to what they wish or need to know. Not knowing feels uncomfortable, and the only relief is to close the gap.
The critter double-clicks a link on a website, because that's how it opens things on its computer.
Users have a preconceived opinion of how things work
A mental model is someone's own explanation of how something in the world operates. It's their inner picture of their surroundings, and it may be right or wrong. What users think they know about a product shapes how they use it.
Seen in: Articos, slide 8, bonds, slide 6
On holiday in a new city, the critter walks past ten local cafés and into a chain it knows from home.
People prefer familiar experiences
People are naturally drawn to what they already know. The more often they meet something, the more they tend to like it. So when building something new, lean on patterns people have seen before.
The critter's first e-reader shows a page that 'turns' like paper, and it knows straight away how to read on it.
Users adapt more easily to things that look like real-world objects
Skeuomorphism makes a digital object copy its real-world version, in looks or in how you handle it, to ease people into new technology. It draws on affordance (the actions people think an object allows) and on Familiarity Bias. It helps most when people are adapting to new interfaces, and since most users are now at home with screens, using it just for looks may not work and can clutter the design.
The shop gives the critter a free sample of cheese, and it feels a little rude not to buy some.
People feel the need to reciprocate when they receive something
Reciprocity is the social habit of returning a kindness with a kindness. In products, people engage more, and trust more, when the product gives them something useful first. That matters most just before a big ask, like signing up or paying.
Seen in: Okara, slide 2, Givingli, slide 5
The critter scrolls past a headline about thousands of flood victims, then stops and donates for one photo of a wet dog on a roof.
Users care disproportionately about an individual as compared to a group
People feel more for one identifiable person than for a large, faceless group. Adding more people doesn't raise the will to help in step; compassion actually fades as the numbers grow. Along with Narrative Bias and the Character Identification Effect, it explains why stories with vivid characters stick in memory far better than statistics.
The critter keeps checking the letterbox, because sometimes, just sometimes, there's a parcel.
People especially enjoy unexpected rewards
In operant conditioning, a variable-ratio schedule rewards a response after a number of tries that can't be predicted. The unpredictable timing keeps people responding at a high, steady rate.
The critter fights with its new robot vacuum for a week, then comes home to a clean floor and finally gets why people love them.
When new users first realize the value of your product
The aha moment is a flash of sudden understanding. In software, it's the turning point when a new user first sees what the product is worth to them.
Seen in: GenPage, slide 5, CraveLens, slide 2, bonds, slide 2
Two stamps away from a free coffee, the critter suddenly goes to that café every day.
Motivation increases as users get closer to their goal
The nearer people get to a milestone, like finishing a task or hitting a goal, the faster they push towards it. Even a made-up or estimated progress bar can spur them on. So make progress clearly visible as feedback.
Seen in: Articos, slide 10
The critter's laptop won't turn on. Before taking it apart, it checks whether it's plugged in. It wasn't.
Simple solutions are often better than the more complex ones
Occam's razor is a rule of thumb: don't use more when less will do, so the simplest explanation is usually the right one. Simple doesn't mean dropping important facts to cut complexity. It takes an open mind to find a better answer that needs fewer parts and fewer assumptions.
Seen in: Siteprint, slide 9
Two near-identical soaps on the shelf; the critter picks the one that plants a tree with every bar.
Users tend to prefer socially responsible companies
Companies that show real care and act with social responsibility usually see it paid back. Customers stay more loyal, and profits rise.
The critter tidies its desk and sits up straight the day the boss walks round the office.
Users change their behavior when they know they are being observed
The Hawthorne effect describes people changing how they behave because they know someone is watching. It is a kind of reactivity: being observed is itself enough to shift what they do.
Seen in: bonds, slide 7
The new neighbour is friendly and well dressed, so the critter assumes they must also be great at their job.
People judge things (or people) based on their feelings towards one trait
A single standout quality, like good looks, a well-known name or a slick website, tints how people rate everything else about someone or something. An attractive landing page sets people up to expect a good product. It cuts both ways, though: one poor moment can drag down the whole impression.
The critter repeats a phone number under its breath all the way to the phone, then forgets the last three digits.
Users can only keep 7±2 items in their working memory
Working memory can only hold a few items at once, often quoted as 7 ± 2, with later studies suggesting nearer 4. Don't make users carry codes, steps or options in their head across screens. Group them, keep them on screen, or trim them.
Given a bigger bowl, the critter eats more cereal, and still feels it had 'one bowl'.
One unit of something feels like the optimal amount
People take a single unit, one plate, one bowl or one pack, as the right portion, however large it is. So the size of a serving or package quietly decides how much gets used. Make the default unit bigger and people use more.
The critter sits down to tidy one drawer and looks up three hours later with the whole room done.
Being fully immersed and focused on a task
Flow is being so absorbed in a task that time slips away, effort feels light and distractions don't get through. It needs a clear goal, fast feedback and a challenge that fits the person's skill. Pop-ups, delays and interruptions knock people out of it.
A man in a white coat on TV recommends a toothpaste, and the critter buys it without asking if he's a dentist.
Users attribute more importance to the opinion of an authority figure
People put extra trust in what experts, famous names or people in uniform say, sometimes no matter what the words are. Quotes from experts, certificates and familiar logos earn trust fast. If that borrowed authority proves fake, trust collapses just as fast.
The critter has four of the five cereal-box toys. It buys a fifth box it doesn't want, just to finish the set.
Tasks that are part of a group are more tempting to complete
When tasks look like pieces of a set, such as 3 of 5 done or a row of badges, they feel a pull to fill the set, even when no single piece matters much. Collections and checklists draw people on, because an empty slot asks to be filled.
The critter loves the group photo from the party, then zooms in and doesn't love its own face at all.
Individual items seem more attractive when presented in a group
Things shown together look better than the same things shown one at a time, because the group covers for the weaker ones. That's why a bundle, a gallery or a grid of samples can lift every piece in it.
The critter's friend gives directions: 'Left at where the old bakery used to be.' The critter has never seen the old bakery.
Not realizing that people don't have the same level of knowledge
Once you know something, it's hard to picture not knowing it. So experts skip steps and use words newcomers don't know yet. Product teams suffer from this most; sit with a beginner as they use the product and note the words that trip them up.
Seen in: Okara, slide 7, Skreno, slide 8
The critter ignores the gym's emails, but when its own phone alarm says 'gym, 7 am', it goes.
Users are more likely to interact with prompts they setup for themselves
Reminders people asked for work much better than ones sent unasked. Let users pick what they get reminded about, and when. A reminder they chose feels like a promise they made to themselves rather than nagging.
Asked how often it exercises, the critter ticks 'three times a week'. It means 'three times a week in January'.
Users tend to skew survey answers towards what's socially acceptable
When describing themselves, people drift towards answers that sound good, clever or acceptable, which aren't always true. What users report and how they really behave often don't match, so back up surveys with real behaviour.
The critter cares about the planet and also really wants that cheap flight, so it decides one flight doesn't really count.
It's painful to hold two opposing ideas in our mind
Holding two clashing ideas, or acting against our own beliefs, is uncomfortable. To ease it, people change a belief, a behaviour or the account they give themselves. After a big purchase, for example, they search for reasons it was the right call, so a reassuring word once they've committed helps them feel settled.
The critter hovers over 'Send' and sees 'to the whole team (48 people)'. It changes its mind.
When users know what to expect before they take action
Feedforward shows people the result of an action before they take it, through a clear label on the button, a preview or a warning like '3 files will be deleted'. Feedback reports what just happened; feedforward takes the guesswork out beforehand.
Seen in: GenPage, slide 9, Hemory, slide 9, CraveLens, slide 9, bonds, slide 9
The critter's team loses the final, and it tells everyone it always knew the goalkeeper was weak.
People overestimate their ability to predict outcomes after the fact
Once something has happened, people feel they saw it coming and think it was easier to predict than it really was. It makes reviews after the fact unfair and their lessons too neat. Record your forecasts ahead of the result.
Every green button in the app so far has meant 'go ahead', so the critter taps the green one without reading it.
Users perceive a relationship between elements that look similar
Things that share a colour, shape or size get read as related or as having the same job. Keep things that behave alike looking alike, and give different things a different look. A link styled like body text vanishes.
The critter looks at a square with a circle over one corner and sees two simple shapes, not one strange outline.
Users interpret ambiguous images in a simpler and more complete form
Also known as the law of simplicity: people read complex or unclear shapes in the simplest way they can. Plain shapes and layouts are grasped faster and remembered better. The mind simplifies on its own regardless, and not always correctly.
The critter's sister says, 'Whatever you do, don't read my diary.' Now the critter can think of nothing else.
When trying to censor information ends up increasing awareness of that information
Trying to hide, remove or censor something often makes many more people go looking for it. Quietly pulling a feature or deleting a bad review can attract more notice than the original ever did. Being open about it usually goes over better.
The critter spills coffee on its shirt and spends the whole meeting sure everyone is staring. Nobody noticed.
People tend to believe they are being noticed more than they really are
People believe others notice their appearance and slip-ups far more than they actually do. That makes users nervous about anything public, like posting, sharing or asking a question. Letting them start privately, with mild defaults, lowers the worry.
The critter will start eating better on Monday. Not today, it's Thursday; Monday is a proper start.
Users are more likely to take action if there's a feeling of new beginnings
People are more willing to start a new habit at a new beginning, like a Monday, the first of the month, a birthday or New Year. Pick one of those moments for a prompt, or create one like 'Day 1', and more people begin.
The critter trusts the pizza more because it watched the chef stretch the dough and slide it into the oven.
People value things more when they see the work behind them
When people wait for something they asked for and can see the work being done, it looks like real effort. They tend to value the result more because of it. It's also known as the KAYAK effect, named for the travel site that did this.
Seen in: Articos, slide 4, Givingli, slide 6, Siteprint, slide 2
The critter has had the same phone ringtone for six years. It's the one the phone came with.
Users tend not to change an established behavior
Unless there's a strong reason to change, people tend to stay with whatever default they're given. It's also called status quo bias, and it can be a strong force when trying to shift behaviour.
Seen in: Articos, slide 2
After months of adding songs to its playlists, the critter can't imagine switching to another music app.
When users invest themselves, they're more likely to come back
People put time, money, data or effort into a product expecting it to pay off later. That investment raises how much the product seems worth to them, so they're more likely to come back. Done well, each investment sets up the next trigger to use it.
The critter barely smiles when it finds $20 in a coat, but loses $20 and it's grumpy all day.
People prefer to avoid losses more than earning equivalent gains
Losing something feels worse than gaining the same thing feels good. Prospect theory puts it in money: dropping $1,000 stings more than finding $1,000 pleases. So people fight hard to keep what they have, even when more is on offer, which can also pull them into the sunk cost trap. See also: Endowment Effect.
Seen in: pushr, slide 6, bonds, slide 4
The critter agreed to water the neighbour's plants for one weekend. Now it's feeding their cat for two weeks.
Users tend to be consistent with their previous actions
Being asked to do something can feel like a threat to the brain. A small first request sets off only a mild fight-or-flight reaction, so people are more likely to say yes, and then to agree to bigger requests step by step, since the brain likes to act in line with what it already did. That's partly why a form split into several steps can do as much as 271% better than one long form.
The critter hates the film after twenty minutes but stays to the end, because the ticket was expensive.
Users are reluctant to pull out of something they're invested in.
The sunk cost effect is carrying on with something because of the time, money or effort already put into it. It turns into a fallacy when it keeps people on a path that no longer pays off.
A sign says 'Do not touch the paint', and the critter feels a strange urge to touch the paint.
Users are less likely to adopt a behavior when they feel forced
Reactance is the pushback people feel when someone or something seems to take away their choices or narrow their options. It produces the opposite of what was intended and makes people harder to persuade.
Seen in: Pip, slide 4
The critter has just learned to make spreadsheets, and now its shopping list, its holiday and its feelings are all in one.
If all you have is a hammer, everything looks like a nail
Once people learn a new skill, they start seeing chances to use it everywhere. Its other names are Maslow's hammer and the law of the hammer, after a line by psychologist Abraham Maslow: if all you hold is a hammer, everything starts to look like a nail.
The critter only lets itself listen to its favourite podcast while doing the ironing, and the ironing gets done.
Hard tasks are less scary when coupled with something users desire
People are more likely to do hard things when they're tied closely to something they enjoy. Research found that pairing a 'want', something that gives instant pleasure, with a 'should', something worthwhile that pays off later, raises the odds that people follow through.
After one cooking video, the critter is sure it can make a soufflé for eight. It can't.
People tend to overestimate their skills when they don't know much
When people know little about a field, that very lack can lead them to overrate their own skill. The flip side is that people who excel tend to assume the task is easy for everyone (see Curse of Knowledge) and underrate how able they are compared with others.
The critter used its oven for a year before discovering it had a timer, behind an unlabelled button.
The ease with which users can discover your features
Discoverability is how well people can work out what a product does and how to use it just by looking at it. When the key controls for taking action are clearly shown, discoverability is good.
Seen in: GenPage, slide 6, CraveLens, slide 4
The critter buys a dog to get more exercise; now it also needs a bigger car, a dog sitter and a new sofa.
The consequences of the consequences of actions
One decision can set off a chain of causes and effects, and it's hard to foresee or control all of them. Even so, people who build products have an ethical duty to try their best to anticipate the harmful side effects of what they make.
Seen in: Siteprint, slide 7, bonds, slide 5
After a day of choosing tiles, taps and paint for its kitchen, the critter can't decide what to have for dinner and eats cereal.
Making a lot of decisions lowers users' ability to make rational ones
Each choice drains a bit of mental energy, and after a long run of them people decide badly, take whatever is preselected, or postpone. A long setup that asks something on every screen tires people out before they reach what matters. Ask fewer questions, ask them later, or make sensible choices on their behalf.
The critter's friend asks, 'You love my new haircut, don't you?' The critter says yes.
When researchers' biases influence the participants of an experiment
Researchers who expect a certain result can push people towards it by accident, with how they phrase things, their tone or how they react. When testing with users, a leading question gets the answer you hoped for rather than the truth. Keep questions neutral and pay attention to behaviour, not answers.
The critter never notices its chocolate bar getting a little smaller each year, until it compares it with an old wrapper.
Users adapt better to small incremental changes
People notice change compared with what came before, not in absolute amounts, so small steps often slip by. Big redesigns jolt users, while small, steady changes give them time to adjust. Prices work the same way.
The critter has a month to write a two-page letter and writes it the night before.
The time required to complete a task will take as much time as allowed
Work stretches to fill whatever time it's given: give it a week and a week is what it takes. Short, clear time frames, like 'takes 2 minutes', make it easier to begin and to get done, while tasks with no end date tend to linger.
In a great mood after a sunny walk, the critter signs up for the expensive gym on the spot.
People's current emotions cloud and influence their judgment
How people feel shapes how they weigh risks and benefits. In a good mood risks seem small; in a bad one everything seems risky. A calm, friendly experience leaves people more open, and a frightening error at a bad time sours everything after it.
The critter knows saving for a holiday is smart, then buys a $6 coffee every morning.
People tend to prioritize immediate benefits over bigger future gains
People would rather have a small reward now than a larger one later, and the nearer a reward is, the harder it pulls. Products whose payoff comes 'one day' have a hard time. Give users a quick win straight away, then the bigger payoff.
Five minutes on hold with silence feels like twenty to the critter; five minutes chatting with a friend flies by.
People's perception of time is subjective
Time as it feels isn't time as it is. A wait with nothing to do drags, while being busy or entertained makes it fly. Showing progress, breaking the wait into steps or giving people something to watch shortens how the wait feels, if not the wait itself.
The critter is careful with banknotes, but taps its phone for three snacks and a magazine without a thought.
People spend more when they can't actually see the money
When paying stops feeling like parting with cash, as with cards, phones, stored credit or one-click checkout, people spend more. The less people see the money go, the less paying hurts, and the larger the total.
When the critter's cake rises, it's a great baker. When it sinks, it's the oven's fault.
People take credits for positive events and blame others if negative
People take the credit when things go well and blame others, or the tool, when they go badly. So when a product lets a user down, they rarely fault themselves; they fault the product, and they tell other people.
The critter owns a full wardrobe but wears the same five favourite outfits almost every week.
Roughly 80% of the effects come from 20% of the causes
Roughly 80% of outcomes trace back to 20% of the causes. Most use comes from a handful of features, and most complaints from a handful of problems. Find that vital 20% and get it right before you polish anything else.
The critter's friend shows it an article proving its favourite diet doesn't work, and the critter defends the diet even more.
When people's convictions are challenged, their beliefs get stronger
When strong beliefs meet contradicting facts, some people dig in harder instead of changing their minds. Correcting users head-on seldom works. Start from where they are and show them rather than argue.
The critter loves pineapple on pizza and orders three for the party, sure everyone else does too.
People overestimate how much other people agree with them
People overestimate how much others share their thoughts, tastes and habits. Teams tend to design for people like themselves, expecting users to match their skills and taste. Try it with people unlike yourself.
Everyone at work starts doing a daily word puzzle, so the critter downloads it too.
Users tend to adopt beliefs in proportion of others who have already done so
The more people take something up, the more others follow, whether or not it's any good. Visible numbers like '10,000 teams use this' draw people in, but the crowd can also sweep them towards something that doesn't suit them.
The critter reads its horoscope, 'You sometimes doubt yourself but are strong inside', and thinks, 'That's so me.'
When you believe generic personality descriptions apply specifically to you.
Broad, vague descriptions feel to people as though they were made just for them. That's what makes horoscopes and personality quizzes seem spot on. 'Personalised' results that would fit nearly anyone can still feel very personal, which is powerful and easy to abuse.
The critter's self-assembled bookshelf leans slightly to the left. It's still the critter's favourite piece of furniture.
When user partially create something, they value it way more
Having a hand in making something makes people value it more, even when the result is a bit shaky. So invite users to assemble, tailor or configure part of the product themselves; they'll grow more attached.
Seen in: Givingli, slide 9
The critter plans to paint the hallway in an afternoon. Three weekends later, it's still doing the corners.
People tend to underestimate how much time a task will take
People expect their own work to take less time than it does, even after past tasks like it ran over. Give realistic time estimates, such as 'about 10 minutes', and assume your own roadmap is likely too hopeful as well.
The meditation app tells the critter, 'That's it for today, see you tomorrow', and the critter happily puts the phone down.
Invite users to leave your app at the right moment
Exit points respect people's time. They are natural moments to put the product down when users feel they've got what they came for. They matter for avoiding product fatigue and reactance (see also: Peak-End Rule).
Seen in: Givingli, slide 4
The holiday had a lost suitcase and two rainy days, but the critter only remembers the sunset dinner on the last night.
People judge an experience by its peak and how it ends.
People don't judge an experience by averaging every small moment. Their memory leans heavily on the high and low points and on how it ended. Pleasant peaks often come from memorable little delights placed along the journey.
The critter only meant to walk past the coffee shop, but the smell of fresh coffee pulled it inside.
Users engage more with things appealing to multiple senses
On a morning walk past a bakery, the smell of fresh bread can be enough to stop us in our tracks. Products are designed to reach people through sight, sound, touch, taste and smell. The more senses involved, the more likely people are to form an emotional bond with the brand.
The critter can't stop thinking about the half-finished puzzle on the table, but it has forgotten the one it finished last week.
People remember incomplete tasks better than completed ones
A task that has been started but not finished keeps a hold on the mind. Kurt Lewin's field theory explains it as a tension that starting a task builds and only finishing it lets go. If the work is interrupted, the tension stays, and so the details of the half-done task stay easy to bring back.
The critter wouldn't pay $10 for its old mug at a car-boot sale, but it won't sell it for $20 either. It's its mug.
Users value something more if they feel it's theirs
People want to keep what they own more than they'd want to get the same thing if they didn't own it. They tend to value their own things above what the market says they're worth. See also: Loss Aversion.
The critter can't remember 07700900123, but it can remember 07700 900 123.
People remember grouped information better
In cognitive psychology, chunking means grouping separate pieces of information into larger units that make sense together. Chunks get around the small capacity of working memory (see Miller's Law) and are easier to recall, because the brain stores each chunk as a single higher-level idea. In design, break steps, copy and screen elements into small bites people can take in and remember.
Seen in: GenPage, slide 4
The hotel leaves a tiny chocolate shaped like the critter's suitcase on the pillow, and the critter tells everyone about it.
People remember more unexpected and playful pleasures
Small, unexpected, playful touches stick in people's memory and make them feel good. But they only work once the basics meet or beat what users expect; otherwise the moment falls flat. And over time, a delight becomes something people expect, and it loses its edge.
Seen in: Givingli, slide 2, CraveLens, slide 7, bonds, slide 3
Every time the critter feels bored in a queue, its paw is already reaching for its phone.
When users are prompted to take action based on a memory
Triggers are prompts to take action, and there are two kinds: external ones like emails, notifications and ads, and internal ones like places, situations, feelings and people. External triggers alert people when something happens. Over time, people link them to internal triggers tied to habits and emotions they already have, until a certain feeling alone is enough to prompt them.
The critter can't remember the name of the café, but it remembers exactly what the striped awning looked like.
People remember pictures better than words
Pictures stick in memory far better than words. Days later, people recall much more from images than from text. Adding a picture, diagram or icon next to a key idea makes it last.
Seen in: Siteprint, slide 5
To remember its shopping, the critter pictures milk on the doormat, eggs on the sofa and bread in the bath.
People remember things more when they're associated with a location
An old memory technique: people recall things better when they tie them to places they know well, such as the rooms in their house. In products, items that never move are easy to locate a second time; shuffling them around erases what people learned.
Seen in: Hemory, slide 4
The critter teaches its dog to fetch: first a treat for looking at the ball, then for touching it, then for bringing it back.
Incrementally reinforcing actions to get closer to a target behavior
Shaping grows a behaviour step by step, rewarding each move that brings someone closer to the goal. Don't expect the whole habit on day one: reward a first small move, then the one after it.
The critter can't name its old teacher, but picks her out of a school photo straight away.
It's easier to recognize things than recall them from memory
Spotting something you can see is far easier than pulling it from memory without any hints. Show choices, recent items and suggestions rather than asking people to recall names, codes or commands.
Seen in: GenPage, slide 3
The critter forgets every statistic from the safety talk, but remembers the story about the man whose ladder slipped.
People remember stories better than facts alone
Stories stick far better than lists of facts, because a story puts facts in sequence, gives them a reason and attaches a feeling. Tell a product's story through someone who used it, rather than a list of features and figures.
Seen in: Pip, slide 5
The critter got ten nice comments on its painting and one mean one, and it's the mean one it reads again at night.
Users recall negative events more than positive ones
Bad experiences count for more and linger longer than equally sized good ones. A single error, a lost piece of work or a rude message can outweigh plenty of good moments, so fix the bad ones first.
Seen in: pushr, slide 2
After watching a shark film, the critter decides swimming in the sea is too dangerous, though it drives to the beach every day.
Users favor recent and available information over past information
People rate a thing's odds or importance by how quickly an example springs to mind; recent and vivid ones arrive first. So whatever users saw last, like the newest review, the latest bug or today's headlines, sways them more than the whole story.
Ten minutes of Spanish a day sticks with the critter far better than a three-hour cram the night before the trip.
People learn more effectively when study sessions are spaced out
Spreading practice across several days teaches more, and sticks longer, than cramming it all into one sitting. Short lessons with breaks between them, returning to an idea a few days on, work better than one long tutorial.
From a shopping list of ten things, the critter comes back with the first two and the last one.
It's easier for users to recall the first and last items of a list
In a list, the items at the top (primacy) and at the bottom (recency) stick best, and the middle fades. Place key options first or last in a list or menu rather than burying them halfway down.
The critter's washing machine shows '38 min left', so it goes off to make tea instead of standing there wondering.
Always show people what is happening
A product should always tell people what it's doing: loading, saving, thinking, done or stuck, and soon enough for them to act on it.
When the screen goes quiet, people guess, wait, click again or leave. A short honest status line beats a pretty spinner that says nothing.
Seen in: Okara, slide 3, Articos, slide 5, Skreno, slide 3, GenPage, slide 7, CraveLens, slide 5
The critter's oven says 'Fan 180°' instead of 'Mode 4B', and it knows exactly what that means.
Speak the user's language, not the system's
Use words, ideas and order that make sense to the people using the product, not the terms the team or the code uses.
Jargon, internal names and raw numbers make people feel stupid. If a word needs explaining, it's probably the wrong word.
Teardowns: Okara
Seen in: Okara, slide 9
The critter deletes a photo by accident and breathes again when it finds the 'Recently deleted' folder.
Give people a clear way back, out and undo
People make mistakes and change their minds. They need an obvious way to undo, go back or leave without losing their work.
When there is no way back, every click feels risky, and people slow down or don't start.
Teardowns: Articos
Seen in: Articos, slide 7, pushr, slide 4, Tiny Little Office, slide 5, Siteprint, slide 6, Hemory, slide 7
In the critter's new car, the windscreen-wiper stalk is where the indicator usually is, and it waves the wipers at every turn.
Things should mean what people expect them to mean
The same word, icon or pattern should mean the same thing everywhere in a product, and match the conventions people know from other products.
When a familiar sign means something new, people misread it with full confidence.
Teardowns: Articos
Seen in: Articos, slide 6, Tiny Little Office, slide 4
The critter's email asks, 'You wrote "attached" but there's no attachment, send anyway?' It wasn't attached.
Stop mistakes before they happen
Better than a good error message is a design that makes the mistake hard to make: sensible defaults, limits, confirmations for risky actions.
Catch the problem where it starts (the wrong account, the wrong file, the wrong date) instead of explaining it three screens later.
Teardowns: Okara
The ticket machine says, 'Card declined. Try another card, or pay with cash at the window.' The critter knows exactly where to go.
Errors should say what went wrong and what to do next
A good error message says in plain words what happened, why, and what the person can do about it.
Codes and dead ends leave people stuck. One clear next step, or a button that does it, turns a failure into a detour.
Teardowns: Okara
Seen in: Okara, slide 6
On a new shopping site, the critter looks for the basket in the top right corner, because that's where it always is.
People expect your product to work like the ones they already use
People spend most of their time in other products, so they bring those habits with them: where the menu is, what a cart icon does, how sign-in works.
Follow the patterns people already know unless there's a strong reason not to. Being different costs users effort.
Seen in: Articos, slide 9, Skreno, slide 5
The critter's old laptop takes two seconds to open each folder, and by the third one it has forgotten what it was looking for.
Under about 400 ms feels instant; longer waits need feedback
When a product responds in under about 0.4 seconds, people stay in the flow and keep going. Slower than that, attention starts to drift.
If something can't be fast, show that it's working and how long it will take, so the wait feels shorter and safer.
On the café board, the critter assumes everything inside the chalk box is part of the lunch deal.
Things inside one border are seen as one group
Elements placed inside the same box, card or background colour are read as belonging together, even if they look different.
A border or a shaded area is a quick way to group things, and a wrongly placed one groups the wrong things.
Seen in: Tiny Little Office, slide 6
Faced with 30 kinds of jam, the critter stands there for five minutes and leaves with none.
Too many options, and people choose nothing
More choice sounds good, but past a point it makes people anxious about choosing wrong, so they delay or walk away.
Fewer, clearer options, a recommended pick, or a filter help people decide and feel good about it.
The critter has paid too much for the same phone contract for years, because switching feels like a hassle.
People stick with what is already set
Changing anything (a plan, a provider, a setting) feels like a risk, so people keep the current state even when something better is on offer.
It's why switching is hard to sell, and why what you set at the start tends to stay. It works closely with Default Bias.
Seen in: Tiny Little Office, slide 2
The critter's new coffee card comes with two stamps already on it, and it fills the rest in a week.
A head start makes people more likely to finish
People who are given some progress up front ('2 of 10 done') are more likely to finish than people starting from zero, even when the work left is the same.
Count the steps they have already taken, like signing up, as progress.
Seen in: Givingli, slide 10, GenPage, slide 2
The critter agrees to sign a petition, and a week later it's handing out leaflets on Saturday.
A small yes makes a bigger yes easier
People who agree to a small request are more likely to agree to a bigger one later; they now see themselves as someone who says yes.
Ask for the small, easy thing first (an email, one permission) and earn the next ask. Jumping to the big ask first often ends in no.
The critter happily shares its location with the map app to find the station, but says no when a torch app asks for it.
People weigh what they give against what they get
Before sharing data or granting access, people weigh the risk against the benefit, and the benefit has to be clear first.
Asking for everything up front, before showing any value, tips the scales towards no. Explain why, ask only for what is needed, and ask when it makes sense.
Teardowns: Pip
Seen in: Pip, slide 3, Givingli, slide 3, pushr, slide 3, Tiny Little Office, slide 9, Hemory, slide 3, CraveLens, slide 3
The critter orders the dish it understands rather than the 'chef's surprise', even though it's the same price.
People avoid options whose outcome is unclear
Given a known risk and an unknown one, people pick the known one, even when the unknown might be better.
Unclear steps, vague prices or a 'Connect' button with no hint of what it connects to make people hesitate. Say what will happen.
Teardowns: Okara
Seen in: Okara, slide 5, Givingli, slide 7
The critter takes the free tote bag it will never use, and walks past the useful one for $1.
"Free" pulls far more than "almost free"
A free thing feels different from a cheap thing: there is no downside to weigh, so people grab it, sometimes over a better deal.
A free trial or a free tier gets people in the door. The harder part is what happens when free runs out.
Teardowns: Pip
In a taxi, the critter watches the meter tick up and can't enjoy the ride. On the flat-fare train, it reads a book.
Per-use prices hurt more than flat ones
Paying hurts, and it hurts more when people feel the meter running: every message, every question, every minute.
A flat price lets people use the product without counting. Per-use pricing makes every use a small decision.
Teardowns: Pip
Seen in: Pip, slide 6
The critter didn't like the new song at first, but after hearing it on the radio all week, it's humming it.
Familiar things feel safer and more likable
The more often people see something, the more they tend to like and trust it, even without noticing they've seen it.
A name, a logo or a face seen many times feels safer than a new one, which helps established products and makes new ones work harder.
The sat-nav says turn left, so the critter turns left, straight into a field.
People over-trust what the machine says
People tend to accept a computer's or an AI's answer without checking it, and to miss errors they'd catch if a person had said the same thing.
AI products should make checking easy: show sources, show uncertainty, and keep a person in the loop for decisions that matter.
The weather app said sunny and the critter got soaked. Now it looks out of the window instead.
One visible AI mistake and people stop trusting it
People forgive humans for mistakes far more readily than machines. After seeing an algorithm get something wrong once, many stop using it, even if it's usually better than them.
Let people correct and adjust the AI's answer, and admit its limits up front, so one miss doesn't end the relationship.
Teardowns: Pip
Seen in: Pip, slide 7
The critter's new spell-checker underlines words in blue when it's sure and grey when it's guessing, so the critter only double-checks the grey ones.
Trust should match what the AI can really do
People should trust an AI tool as much as it deserves, no more and no less. Too much trust leads to errors slipping through; too little wastes what it can do.
Showing how sure the AI is, where its answer came from and where it tends to fail helps people find the right level of trust.
Seen in: Okara, slide 8, pushr, slide 7, Hemory, slide 2, CraveLens, slide 6