Every term worth knowing — a concept library for designers, PMs, engineers, founders, and tech leaders. Page 3 of 11.

Color Wheel

A circular diagram of hues in spectrum order, where position shows which colors look related and which contrast most.

Contextual inquiry

A field research method where a researcher watches people do their real work in their own setting and asks questions as they work.

Distribution Channel

A distribution channel is the route, direct or through intermediaries such as wholesalers and retailers, by which a product reaches the customer who buys it.

Evidence based design

A design method that bases decisions about buildings on credible research, predicts what each choice will change, and measures the result after people move in.

Eye Tracking

Eye tracking measures where a person looks and how their gaze moves, using a camera to follow the pupil and a light reflection on the eye.

Levels of Awareness

Eugene Schwartz's model of how much a prospect knows about a need, its solutions and your product, which decides what a message should say.

Minimum Viable Offer

The smallest offer, with one promise, one price and one way to buy, that gets real customers to pay before the product is built.

Mixture of Experts

A model design that stores many sub-networks, called experts, and runs only a few of them per input, so capacity grows faster than compute cost.

Spotlight Effect

The spotlight effect is the tendency to overestimate how much other people notice your appearance, mistakes, and behavior, compared with how much they actually notice.

Uncanny Valley

The dip in comfort people feel toward a robot, animated character, or synthetic face as its human likeness approaches, but does not quite reach, fully realistic.

Wizard of Oz

A test in which a hidden person secretly plays the part of a system that does not exist yet, so designers can watch real users react.

Affinity diagramming

A team method for sorting many separate observations or ideas into named groups by how closely they relate.

Barnum Effect

The tendency to accept a vague, general personality description as uniquely accurate for you when you believe it was written for you.

Confirmshaming

A dark pattern that words the decline option as a flaw in the person, such as No thanks, I hate saving money, to make them accept.

Distillation

A technique where a small model is trained to copy the behavior of a large one, keeping most of the accuracy while being cheaper and faster to run.

Experience prototyping

Experience prototyping is a design method in which people act out or live through a rough version of a future product, space or service to feel what using it is like.

Gambler's Fallacy

The mistaken belief that an independent random event is more likely to happen because it hasn't happened recently, even though the odds of each trial never change.

Law of Common Fate

The Law of Common Fate is the Gestalt principle that elements moving or changing in the same way at the same time are seen as one group.

Perplexity

The metric that measures how well a language model predicts a text: the exponential of its average negative log-probability per token.

Variance

Variance measures how far values in a data set spread from their mean, as the average of the squared distances to the mean.

Z-Pattern

The Z-pattern is a layout model in which a viewer's eyes cross the top of a page, jump diagonally to the lower left, then cross the bottom.

Customer experience audit

A structured review that compares the experience customers actually have with the one a company intends to give, across the whole customer journey.

Gutenberg Diagram

The Gutenberg diagram is a layout model that predicts a left-to-right reader moves from the top-left corner of an evenly filled page to the bottom-right corner.

Storyboards

A sequence of drawn panels, each with a short caption, that shows one person moving through a situation so a team can plan and discuss it.

Brand Equity

The extra value a brand name adds to a product, shown in the price, loyalty and trust buyers give it.

Content inventory and audit

A two-part review of existing content: an inventory lists every page and file with facts about it, and an audit judges each item and decides whether to keep, update or remove it.

EAST Framework

A four-part checklist for encouraging a behaviour: make it Easy, Attractive, Social and Timely, by changing how the choice is set up.

Index of Difficulty

The index of difficulty scores, in bits, how hard it is to move a pointer or finger to a target, from the distance to it and its width.

Observer-Expectancy Effect

A research bias in which the expectations of the person running a study unintentionally change what participants do or how results are read.

Risk Reversal

A selling tactic where the seller agrees to pay the cost of a disappointing purchase, so the buyer takes less risk by buying.

Adversarial Attack

A deliberately crafted input, often changed imperceptibly, that makes a machine learning model give a wrong answer.

Attentional Blink

A lapse in noticing a second target that appears within about half a second of a first target in a fast stream of items, even when the observer is looking straight at it.

Comparative Advantage

Comparative advantage is the ability to produce something at a lower opportunity cost than another party, which makes trade beneficial even when one party is better at everything.

Locus of Control

A person's general belief about whether outcomes in their life are caused mainly by their own actions or by forces outside them, such as luck or other people.

Narrative Transport

The state of being so absorbed in a story that imagery, emotion and attention all follow it, which lowers the reader's resistance to its claims.

Recall Bias

A systematic error in studies and surveys where people remember past events wrongly, or differently between groups, which shifts the result.

Active Learning

A machine learning approach where the model selects which unlabeled examples to have labeled next, usually the ones it is least certain about, to reach higher accuracy with fewer labels.

Cocktail Party Effect

The ability to follow one voice among many speaking at once, and to notice personally relevant words, such as your own name, in speech you are ignoring.

Golden Ratio

A proportion of about 1 to 1.618 in which the whole is to the longer part as the longer part is to the shorter, used to set layouts, rectangles and type scales.

Margin of Error

The range around a survey result, in percentage points, that is expected to contain the true population value at a stated confidence level.

Pragmatics

Pragmatics studies how context, shared knowledge and the speaker's purpose give an utterance a meaning beyond its literal words.

Service Blueprints

A diagram that lines up each step a customer takes with the staff work and systems behind it, to show where a service breaks down.

Skeuomorphic Design

Skeuomorphic design copies the look or sound of real objects in an interface so that a new product feels familiar and is easier to learn.

Amortization

Amortization spreads a loan's principal or an intangible asset's cost across a fixed schedule of periods.

ROC Curve

A graph of a classifier's true positive rate against its false positive rate at every decision threshold, showing how well it separates two classes.

Schema Theory

Schema theory says people understand and remember new information by fitting it into general mental patterns, called schemas, built from past experience, rather than storing each experience whole.

Altruism Design

Altruism design builds products whose use involves helping or being helped by another person, by leaving the interaction loop incomplete.

Awe and Wonder

The emotion of meeting something far larger than you expected that does not fit what you know, and the design effect of causing it.

Beam Search

Beam search is a decoding method that keeps the k highest-scoring partial outputs at each step, so a model can compare several candidate sequences without scoring every possible one.

Ben Franklin Effect

The tendency to like a person more after doing them a favour, because the helper treats their own act as a sign of liking.

Zero-Shot Learning

Zero-shot learning lets a model recognise classes or do tasks it has no labelled examples of, using a description such as a label name instead.

Creative matrix

A brainstorming grid that crosses two lists, so a team writes ideas for every pairing of one row and one column.

Commander's Intent

Commander's intent is a short statement of why an operation is happening and what the end state should be, so people can adapt when the plan fails.

Criterion of Justice

A standard for judging whether a distribution of benefits and burdens is fair, used to test whom a nudge actually helps.

Door-in-the-Face

The door-in-the-face technique gains agreement by first making a large request that is likely to be refused, then asking for a much smaller one.

Cooperative Principle

The cooperative principle is Paul Grice's idea that speakers normally contribute what a conversation needs, so listeners can work out meaning that the words do not state.

Kerning

Adjusting the space between two specific letters so the gaps in a line of text look even.

Optical Alignment

Placing shapes, letters and text where they look aligned to the eye, even when measurement says they are off.

Passive Wording

Passive wording is writing in the grammatical passive, where the thing acted on is the subject and the doer can be left out.

Bodystorming

A design method where a team acts out a situation with rough props to find and test ideas in a physical setting.

Stealth Marketing

Promotion in which the audience does not realise a company is behind the message, so it reads as an independent opinion or ordinary content.

The Principle of Charity

The principle of charity is the rule of reading a statement or argument in its most rational form, so you answer what the speaker meant and not a weaker version.

Word clouds

A picture of the words in a text, each drawn at a size that follows how often it appears, which shows counts but not meaning or context.

Collage

A participatory research method in which people arrange images and words into a collage that shows an experience, then explain it to the researcher.

Law of Uniform Connect

Uniform connectedness is the Gestalt principle that elements joined by a line, bar or shared fill are seen as one unit.

Bionic Reading

Bionic Reading is a text format that sets the first letters of each word in bold to guide the eye; tests have found no gain in reading speed.

4E Framework

A pattern for four-part models whose parts all start with E, best known as the marketing swap of the 4Ps for Experience, Exchange, Everyplace and Evangelism.

Bezold Effect

A color illusion in which small areas of two colors blend, so a color looks darker or lighter depending on the colors woven through it.

BLEU Score

An automatic machine translation score that compares output with human reference translations by counting matching word sequences of up to four words, with a penalty for output that is too short.

Doherty Threshold

Walter Doherty and Ahrvind Thadhani's 1982 finding that cutting a computer's response time below about a second raises how much work a person finishes per hour more than proportionally.

The Crusader Rule

A rule from Josh Kaufman's The Personal MBA: evaluate a new business idea against its market before committing, because an exciting idea is not yet a viable business.

Elito method

A design synthesis method that turns each research observation into a row of judgment, value, concept and key metaphor.