A mental model is what users think your product does and how parts connect. When UI violates that model, errors and distrust rise even if the pixels are pretty.
Discover models with research
Interviews, card sorts, and observation show language and metaphors people already use — mirror them in IA and copy.
Metaphors have tails
“Trash” implies recovery; “archive” implies search later. Pick metaphors whose affordances you can support end-to-end.
Repair broken models
When you must diverge from expectations, teach with onboarding, previews, and reversible states — do not silently surprise.
Practices
- Align file metaphors with OS conventions.
- Use the same nouns in UI, docs, and support.
Common pitfalls
- Inventing new verbs for standard actions per screen.
- Hiding state that finance or legal teams expect to see.