Name

One-Liner

Category

Hick’s Law

More options leads to harder decisions

Information

Confirmation Bias

People look for evidence that confirms what they think

Information

Priming

Previous stimuli influence users’ decision

Information

Cognitive Load

Total amount of mental effort that is required to complete a task

Information

Anchoring Bias

Users rely heavily on the first piece of information they see

Information

Nudge

Subtle hints can affect users’ decisions

Information

Progressive Disclosure

Users are less overwhelmed if they’re exposed to complex features later

Information

Fitt’s Law

It’s easier to aim the bigger the target is.

Information

Attentional bias

Users’ thoughts filter what they pay attention to

Information

Empathy Gap

People underestimate how much emotions influence user behaviors

Information

Visual Anchors

Elements used to guide users’ eyes

Information

Von Restorff Effect

People remember more items that stand out

Information

Visual Hierarchy

The order in which people perceive what they see

Information

Selective Attention

People filter out things from their environment when in focus

Information

Survivorship Bias

People neglect things that don’t make it past a selection process

Information

Sensory Adaptation

Users tune out the stuff they get repeatedly exposed to

Information

Juxtaposition

Elements that are close and similar are perceived as a single unit

Information

Signifiers

Elements that communicate what it will do

Information

Contrast

Users’ attention is drawn to higher visual weights

Information

External Trigger

When the information on what to do next is within the prompt itself

Information

Decoy Effect

Create a new option that’s easy to discard

Information

Centre-Stage Effect

People tend to choose the middle option in a set of items

Information

Framing

The way information is presented affects how users make decisions

Information

Law of Proximity

Elements close to each other are usually considered related

Information

Tesler’s Law

If you simplify too much, you’ll transfer some complexity to the users

Information

Spark Effect

Users are more likely to take action when the effort is small

Information

Feedback Loop

When users take action, feedback communicates what happened

Information

Expectations Bias

People tend to be influenced by their own expectations

Information

Aesthetic-Usability Effect

People perceive designs with great aesthetics as easier to use

Information

Social Proof

Users adapt their behaviors based on what others do

Meaning

Scarcity

People value things more when they’re in limited supply

Meaning

Curiosity Gap

Users have a desire to seek out missing information

Meaning

Mental Model

Users have a preconceived opinion of how things work

Meaning

Familiarity Bias

People prefer familiar experiences

Meaning

Halo Effect

People judge things (or people) based on their feelings towards one trait

Meaning

Miller’s Law

Users can only keep 5±2 items in their working memory

Meaning

Unit Bias

One unit of something feels like the optimal amount

Meaning

Flow State

Being fully immersed and focused on a task

Meaning

Skeuomorphism

Users adapt more easily to things that look like real-world objects

Meaning

Reciprocity

People feel the need to reciprocate when they receive something

Meaning

Authority Bias

Users attribute more importance to the opinion of an authority figure

Meaning

Pseudo-Set Framing

Tasks that are part of a group are more tempting to complete

Meaning

Variable Reward

People enjoy rewards, especially unexpected ones

Meaning

Cheerleader Effect

Individual items seem more attractive when presented in a group

Meaning

Curse of Knowledge

Not realizing that people don’t have the same level of knowledge

Meaning

Aha! moment

When new users first realize the value of your product

Meaning

Self-Initiated Triggers

Users are more likely to interact with prompts they setup for themselves

Meaning

Survey Bias

Users tend to skew survey answers towards what’s socially acceptable

Meaning

Cognitive Dissonance

It’s painful to hold to opposing ideas in our mind

Meaning

Goal Gradient Effect

Motivation increases as users get closer to their goal

Meaning

Feedforward

When users know what to expect before they take action

Meaning

Occam’s Razor

Simple solutions are often better than the more complex ones

Meaning

Noble Edge Effect

Users tend to prefer socially responsible companies

Meaning

Hindsight Bias

People overestimate their ability to predict outcomes after the fact

Meaning

Law of Similarity

Users perceive a relationship between elements that look similar

Meaning

Law of Prägnanz

Users interpret ambiguous images in a simpler and more complete form

Meaning

Spotlight Effect

People tend to believe they are being noticed more than they really are

Meaning

Fresh Start Effect

Users are more likely to take action if there’s a feeling of new beginnings

Meaning

Labor Illusion

People value things more when they see the work behind them

Time

Default Bias

Users tend not to change an established behavior

Time

Investment Loops

When users invest themselves, they’re more likely to come back

Time

Loss Aversion

People prefer to avoid losses more than earning equivalent gains

Time

Commitment & Consistency

Users tend to be consistent with their previous actions

Time

Sunk Cost Effect

Users are reluctant to pull out of something they’re invested in.

Time

Decision Fatigue

Making a lot of decisions lowers users’ ability to make rational ones

Time

Reactance

Users are less likely to adopt a behavior when they feel threatened

Time

Observer-Expectancy Effect

When researchers’ biases influence the participants of an experiment

Time

Weber’s Law

Users adapt better to small incremental changes

Time

Law of the Instrument

If all you have is a hammer, everything looks like a nail

Time

Temptation Coupling

Hard tasks are less scary when coupled with something users desire

Time

Parkinson’s Law

The time required to complete a task will take as much time as allowed

Time

Dunning-Kruger Effect

People tend to overestimate their skills when they don’t know much

Time

Affect Heuristic

People’s current emotions cloud and influence their judgment

Time

Hyperbolic Discounting

People tend to prioritize immediate benefits over bigger future gains

Time

Cashless Effect

People spend more when they can’t actually see the money

Time

Self-serving bias

People take credits for positive events and blame others if negative

Time

Pareto Principle

Roughly 80% of the effects come from 20% of the causes

Time

Discoverability

The ease with which users can discover your features

Time

Backfire Effect

When people’s convictions are challenged, their beliefs get stronger

Time

False Consensus Effect

People overestimate how much other people agree with them

Time

Barnum-Forer Effect

Some people believe in astrology and fortune telling.

Time

IKEA Effect

When user partially create something, they value it way more

Time

Planning Fallacy

People tend to underestimate how much time a task will take

Time

Provide Exit Points

Invite users to leave your app at the right moment

Memory

Peak-End Rule

People judge an experience by its peak and how it ends.

Memory

Sensory Appeal

Users engage more with things appealing to multiple senses

Memory

Zeigarnik Effect

People remember incomplete tasks better than completed ones

Memory

Endowment Effect

Users value something more if they feel it’s theirs

Memory

Chunking

People remember grouped information better

Memory

Picture Superiority Effect

People remember pictures better than words

Memory

Method of Loci

People remember things more when they’re associated with a location

Memory

Shaping

Incrementally reinforcing actions to get closer to a target behavior

Memory

Delighters

People remember more unexpected and playful pleasures

Memory

Internal Trigger

When users are prompted to take action based on a memory

Memory

Recognition Over Recall

It’s easier to recognize things than recall them from memory

Memory

Storytelling Effect

People remember stories better than facts alone

Memory

Negativity Bias

Users recall negative events more than positive ones

Memory

Availability Heuristic

Users favor recent and available information over past information

Memory

Spacing Effect

People learn more effectively when study sessions are spaced out

Memory

Serial Position Effect

It’s easier for users to recall the first and last items of a list

Memory