17 · Deciding
Occam's Razor
When two options do the job equally well, pick the one with fewer parts.
Evidence: Rule of thumbWhat we do with it
- 01
Before adding a feature, decide what you'd remove to make room for it.
- 02
Every element should earn its place. If nobody can say what it's for, cut it.
- 03
Simple to use isn't simple to build. The plainest screen often has the most work behind it.
Examples
Getting it wrong, getting it right.
Don't
Three ways to share a document, each built by a different team, each with its own dialog.
Do
One Share button that does all three.
The evidence
What the research says.
As a rule of reasoning it can't be tested. UX research points the same way, though. Debora Thompson, Rebecca Hamilton and Roland Rust found in 2005 that people pick feature-packed products before they use them, then rate them harder to use and less satisfying afterward. Katharina Reinecke and colleagues found in 2013 that how visually complex a website looks, together with how colorful it is and the viewer's age and education, explains about half of how appealing people find it after half a second.
Sources
- William of Ockham (c. 1287–1347). Attributed; the phrase “entities should not be multiplied beyond necessity” came later.
- Thompson, D. V., Hamilton, R. W., & Rust, R. T. (2005). Feature fatigue: When product capabilities become too much of a good thing. Journal of Marketing Research, 42(4).
- Reinecke, K., Yeh, T., Miratrix, L., Mardiko, R., Zhao, Y., Liu, J., & Gajos, K. Z. (2013). Predicting users' first impressions of website aesthetics with a quantification of perceived visual complexity and colorfulness. CHI '13.
Last reviewed November 7, 2026. How we keep this current