Build The System
The laws behind the architecture, governing how teams, systems, and estimates really behave.Tesler’s Law
Complexity never disappears; someone absorbs it.
Gall’s Law
Working systems grow from simple ones.
Conway’s Law
Products mirror the teams that build them.
Postel’s Law
Accept input generously, send output carefully.
Goodhart’s Law
Targets stop measuring once they're targets.
Hofstadter’s Law
Everything takes longer than expected.
Pareto Principle
Eighty percent comes from twenty percent.
Design Actions And Controls
Targets, feedback, and forgiving controls, tuned to how hands and attention actually behave.Fitts’s Law
Big, close targets are faster.
Steering Law
Narrow paths slow the pointer.
Contour Bias
Rounded feels safe; sharp reads urgent.
Navigation Patterns
The proven ways users find things.
Doherty Threshold
Respond within 400 milliseconds.
Power Law of Practice
Repetition makes every task faster.
Yerkes-Dodson Law
Some pressure helps; too much hurts.
Follow The Rulebooks
The canonical checklists and standards that settle arguments and keep quality from drifting.Nielsen’s 10 Heuristics
Ten usability principles — the standard checklist.
Norman’s Principles
The vocabulary of everyday design.
Rams’ 10 Principles
Ten questions good design must answer.
Shneiderman’s Eight Golden Rules
Eight golden rules of interface design.
Tognazzini’s First Principles
Sixteen principles for interaction design.
WCAG and POUR
Perceivable, operable, understandable, robust.
Chesterton’s Fence
Understand it before you remove it.
Keep Them Coming Back
Delight, memory, and habit — the reasons people return long after the first visit.Aesthetic-Usability Effect
Beautiful feels easier to use.
Peak-End Rule
People remember peaks and endings.
Uncanny Valley
Almost-human unsettles more than machines.
Zeigarnik Effect
Unfinished tasks stay on the mind.
Fogg Behavior Model
Behavior needs motivation, ability, a prompt.
Hook Model
Trigger, action, reward, investment — repeat.
IKEA Effect
We overvalue what we help build.
Lay Out The Page
Where the eye goes and why, and how structure decides what gets seen first.Eye-Scanning Patterns
Six scan shapes from eye-tracking research.
Gutenberg Principle
Reading gravity flows toward bottom-right.
Grid and Hierarchy
Grids organize space; hierarchy directs attention.
Gestalt Principles
How the mind groups what it sees.
Von Restorff Effect
The different one gets remembered.
Weber-Fechner Law
Perception scales with ratios, not amounts.
Present And Explain
Making information effortless to absorb, so understanding costs the reader as little as possible.Data Visualization
Sixteen chart types, grouped by question.
Universal Icons
The few glyphs everyone already reads.
Progressive Disclosure
Show essentials now, reveal more later.
Cognitive Load Theory
Working memory is the real bottleneck.
Miller’s Law
About seven chunks, plus or minus two.
Serial Position Effect
First and last stick; middle fades.
Curse of Knowledge
Experts can't imagine not knowing.