Design of Everyday Things Framework

Foundational design principles for creating products that are intuitive, discoverable, and understandable. The "bible of UX" — applicable to physical products, software, and any human-designed system.

Core Principle

Good design is actually a lot harder to notice than poor design, in part because good designs fit our needs so well that the design is invisible. When something fails, users blame themselves — but the fault is almost always in the design. Great design bridges the gap between what people want to do and what the product allows: it is discoverable (you can figure out what to do) and understandable (you can figure out what happened).

Scoring

Goal: 10/10. Score 2 points per satisfied row of the Quick Diagnostic (5 rows = discoverability, evaluation, error recovery, mapping, constraints). Bands: 9-10 = users act without instructions, understand every outcome, and recover from any error; 5-6 = one gulf or error path is broken; <=3 = users must consult a manual or routinely blame themselves. Report the current score and the diagnostic rows failing it.

The Two Gulfs

Every interaction with a product requires bridging two gulfs: