Lay Out The Page
Eye-Scanning Patterns
Six scan shapes from decades of eye-tracking research.
Gutenberg Principle
Reading gravity flows from top-left down to bottom-right.
Grid and Hierarchy
Grids organize space, hierarchy directs attention.
Gestalt Principles
How the mind groups what it sees — proximity, similarity, closure.
Von Restorff Effect
The one that differs is the one that gets remembered.
Weber-Fechner Law
Perception scales with ratios, not absolute amounts.
Present And Explain
Data Visualization
Sixteen chart types grouped by the question they answer.
Universal Icons
The small set of glyphs the whole world already reads.
Progressive Disclosure
Show what matters right now, reveal the rest on demand.
Cognitive Load Theory
Working memory is the bottleneck — cut the interface’s overhead.
Miller’s Law
About seven chunks, plus or minus two — working memory’s limit.
Serial Position Effect
First and last stick, the middle fades — position is memory.
Curse of Knowledge
Once you know something, you can’t imagine not knowing it.
Structure The Choices
Hick’s Law
More choices, longer decisions — and how to keep menus fast.
Jakob’s Law
Users live on other sites — yours should work like them.
Paradox of Choice
More options, fewer decisions — and the patterns that break paralysis.
Automation Bias
People accept what the machine suggests — even when it is wrong.
Design Actions And Controls
Fitts’s Law
Big and close is fast — the law behind every button and tap target.
Steering Law
The narrower the path, the slower the steering gets.
Contour Bias
Rounded shapes feel safe to press — sharp angles read as alerts.
Navigation Patterns
Global, local, utility, breadcrumbs — the layers that place the user.
Doherty Threshold
Under 400 milliseconds, work becomes a conversation.
Power Law of Practice
Task time drops as a power of repetitions — the learning curve.
Yerkes-Dodson Law
Performance rises with arousal, peaks, then falls.
Keep Them Coming Back
Aesthetic-Usability Effect
Beautiful design feels easier to use — polish buys patience and trust.
Peak-End Rule
Experiences get judged by their peak moment and their end.
Uncanny Valley
Almost-human faces, voices, and text unsettle more than machines.
Zeigarnik Effect
Unfinished tasks stay in memory — open loops pull people back.
Fogg Behavior Model
Behavior needs motivation, ability, and a prompt — B = M · A · P.
Hook Model
Trigger, action, variable reward, investment — the habit loop.
IKEA Effect
Users value what they help build — labor turns into ownership.
Build The System
Tesler’s Law
Complexity never disappears — it only moves. Who absorbs it?
Gall’s Law
Working complex systems grow from simple ones that worked.
Conway’s Law
Products come to mirror the org charts that build them.
Postel’s Law
Strict in what you send, forgiving in what you accept.
Goodhart’s Law
When a measure becomes a target, it ceases to measure well.
Hofstadter’s Law
It always takes longer than you expect — even knowing this law.
Pareto Principle
Eighty percent of effects come from twenty percent of causes.
Follow The Rulebooks
Nielsen’s 10 Heuristics
Jakob Nielsen’s ten usability principles — the standard checklist.
Norman’s Principles
Affordances, signifiers, mapping, feedback — Norman’s foundations.
Rams’ 10 Principles
Less, but better — ten principles of good design, fifty years on.
Shneiderman’s Eight Golden Rules
Eight rules that have governed interface design since 1985.
Tognazzini’s First Principles
Sixteen working rules for software that respects the user.
WCAG and POUR
The four POUR principles of accessible interface design.
Chesterton’s Fence
Don’t remove a fence until you know why it’s there.