Interaction design laws
Hick's law
Also called Hick-Hyman law
The time it takes to make a choice grows with the number of options, so fewer, clearer options lead to faster decisions.
Each extra option adds a little to how long a decision takes. The growth slows as options are added, but it adds up across a whole interface.
Cut options people don't need, highlight a recommended one, and break long decisions into steps. It applies most to simple choices between known options, less to browsing.
In practice
A setup screen that asks one question at a time instead of showing every setting at once.
Common mistake
Simplifying so far that people can't find what they need. Fewer options only helps if the right ones remain.
Where it comes from
Described by William Edmund Hick in 1952 and Ray Hyman in 1953, from experiments timing how quickly people responded to different numbers of lights.