Key Principles & Laws

Fitts’s Law

Time to acquire a target increases with distance and decreases with size. Use larger targets, especially at edges and corners.

Hick’s Law

Decision time grows with the number and complexity of choices. Reduce and group options; prefer recognition over recall.

Signal Detection

Balance hits vs false alarms by tuning thresholds; provide clear feedback and redundancy.

Jakob’s Law

Users prefer interfaces that work like familiar ones. Lean on conventions to reduce learning time.

References

• Fitts (1954) — The information capacity of the human motor system. https://doi.org/10.1037/h0055392
• Hick (1952) — On the rate of gain of information. https://doi.org/10.1113/jphysiol.1952.sp004764
• Green & Swets (1966) — Signal Detection Theory and Psychophysics. https://doi.org/10.1002/bs.3830110107
• NN/g — Jakob’s Law: https://www.nngroup.com/articles/jakobs-law/