Hick’s Law
Choosing a response usually takes longer as the number and uncertainty of possible responses increase.
Decision time grows with uncertainty, not with an arbitrary menu limit.
A toolbar contains twenty unlabeled icons. An experienced user may know every position. A new user must inspect each one before acting. The same count creates very different decision time because familiarity changes the uncertainty.
Origin
William Hick's 1952 experiments connected choice reaction time with the information carried by possible responses. The finding concerned defined stimulus-response tasks, so it should not be treated as a universal menu formula.
Remove choices that do not belong at the current step. A focused decision is easier than a screen that asks people to solve the whole workflow at once.
Organize large sets around familiar categories, search, or filters. Better structure can reduce uncertainty without hiding useful options.
Use clear labels and meaningful differences. Six vague options can take longer to judge than twelve options people already understand.
Support expert memory with stable placement and shortcuts. Familiar choices are retrieved differently from options that must be evaluated from scratch.
Digital systems
A grouped action menu
Common actions appear first with clear labels. Less frequent tools sit in named groups. The full capability remains available, but the first decision becomes easier to scan.
Physical signals
A simple emergency control
One large alarm control removes the need to compare several similar switches under pressure. The required response is visible and distinct.
A flat set of unclear choices makes people compare too much before they can act, especially when the options are unfamiliar or similar.
Remove irrelevant choices, group the rest by meaning, write labels people understand, and keep familiar options where people expect them.