Overview
Yablonski (O’Reilly, 2nd ed. 2024) — Applies key principles of psychology to build more human-centered, intuitive products. The most elegant design fails if it forces users to conform to the design instead of working within the blueprint of how humans perceive and process the world.
Laws Covered
| Law | Principle |
|---|---|
| Jakob’s Law | Users spend most of their time on OTHER sites — they prefer your site to work the same way |
| Fitts’s Law | Time to acquire a target is a function of distance to and size of the target |
| Hick’s Law | Time to make a decision increases with the number and complexity of choices |
| Miller’s Law | Average person can hold 7 (±2) items in working memory |
| Postel’s Law | Be liberal in what you accept, conservative in what you send |
| Peak-End Rule | People judge experiences based on the peak and the end, not the average |
| Aesthetic-Usability Effect | Users perceive aesthetically pleasing design as more usable |
| Von Restorff Effect | Items that stand out from the group are more likely to be remembered |
| Tesler’s Law | Every application has an inherent amount of irreducible complexity |
| Doherty Threshold | Productivity soars when a computer and user interact at a pace (<400ms) that ensures neither has to wait |
Second Edition Additions
- AI and spatial computing implications for each law
- Updated UX heuristic connections
- Ethical implications of applying psychology in design
- Practical framework for applying these principles in your design process
Key Insight
Understanding psychology — specifically the psychology behind user behavior and interaction with digital interfaces — is the single most valuable nondesign skill a designer can have.
Related
- designing-for-performance — Hogan’s performance-focused companion — speed as a UX fundamental
- frontend-architecture-design-systems — Godbolt’s architectural framework within which these UX laws operate