Laws of UX

A framework of behavioural psychology principles applied to interface design. These laws describe how humans perceive, decide, and act -- use them to design interfaces that work with human cognition, not against it.

This skill focuses on behavioural laws (Fitts's, Hick's, Miller's, etc.). For usability heuristics, see ux-heuristics. For visual grouping principles, see gestalt-ui.

Core Principle

Design for how humans actually behave, not how they should behave. Users don't read -- they scan. They don't optimise -- they satisfice. They don't remember -- they recognise. Every interaction design decision should be grounded in observable human behaviour, not designer assumptions.

Scoring

Goal: 10/10. When reviewing or designing interactions, rate 0-10 based on alignment with these behavioural laws.

• 9-10: Interactive targets are appropriately sized and placed. Choices are manageable. Response times feel instant. Progress is visible. Memory load is minimal.
• 7-8: Most interactions follow the laws. Minor issues: a few small targets, one overloaded menu, occasional missing feedback.
• 5-6: Some laws applied, others ignored. Noticeable friction: too many choices, missing progress indicators, slow feedback.
• 3-4: Significant violations. Small touch targets, overwhelming option lists, no loading feedback, heavy memory demands.
• 1-2: Laws systematically violated. Interface fights human cognition at every step.