Hick's Law
The time it takes to make a decision increases with the number and complexity of choices. Every option added has a measurable, predictable cost in decision time.
Overview
Named after psychologists William Edmund Hick and Ray Hyman, Hick's Law describes the logarithmic relationship between the number of available choices and the time required to make a decision. It's one of the most directly actionable principles in UX because it gives you a mathematical basis for what you already intuitively sense: more options take longer to process.
The law doesn't say fewer is always better — it says every additional option has a quantifiable cost. In contexts where fast decisions matter — navigation, checkout, onboarding — that cost compounds quickly. A menu with 10 items doesn't take twice as long to process as one with 5; it takes logarithmically longer, which in practice means the difference between a completed task and an abandoned one.
Takeaways
- 01
Minimise the number of choices presented at any one time to reduce decision time and cognitive load.
- 02
Break complex decisions into a series of smaller steps, each with fewer options — a process that feels simpler even when the total number of choices is the same.
- 03
Remove features and options that are rarely used rather than including everything by default. What you leave out is a design decision.
How to Apply This
Simplify navigation.
Navigation menus with 10+ items require significantly more cognitive scanning time than menus with 5–7 items. Group related items, use progressive disclosure for secondary navigation, and surface the most-used paths at the top level. Secondary paths can live behind a single entry point.
Reduce form complexity.
Every unnecessary field adds a micro-decision. Audit forms to remove anything not strictly required. Pre-fill fields from context where possible. Reduce dropdowns with many options to the most common subset, with a fallback path for edge cases.
Streamline onboarding.
Presenting too many features to new users creates paralysis before they've derived any value. Introduce capabilities progressively as users develop familiarity. The goal at first contact is one successful action, not a complete tour of the product.
Common Misconception
Hick's Law is often misapplied as justification for severely limiting features or hiding useful functionality. The law applies to decisions at a specific moment — not to the total number of features in a product. The goal is to surface the right options at the right time, not to have fewer options overall.
Origin
Hick's Law is named after William Edmund Hick, who first published his findings in 1952, and Ray Hyman, who independently developed a similar formulation in 1953. Together, their work established the logarithmic relationship between the number of stimuli (choices) and reaction time — now expressed as RT = a + b × log₂(n + 1), where n is the number of choices. The law was derived from experiments in which participants responded to varying numbers of visual or auditory stimuli, and has since been validated across a wide range of human decision-making contexts.
FAQ
- What is Hick's Law?
- Hick's Law states that the time required to make a decision increases logarithmically with the number of choices available. Formally: RT = a + b × log₂(n + 1). In practice, it means that doubling the number of options doesn't double decision time — but it does increase it predictably, and the cost accumulates across every decision point in a flow.
- How does Hick's Law apply to UX design?
- It directly informs decisions about navigation structure, form design, feature prioritisation, and onboarding. Wherever users must choose between options, Hick's Law predicts that reducing the number of options will reduce decision time — and that reducing decision time will increase task completion rates and perceived ease of use.
- Does Hick's Law mean fewer options are always better?
- No. Hick's Law describes the cost of options at a specific decision point, not a global principle that fewer features are better. A product can have rich functionality as long as it's not all surfaced simultaneously. Progressive disclosure — revealing options progressively as context demands — is the standard design response.
- What is the Hick-Hyman Law?
- Hick's Law is sometimes called the Hick-Hyman Law to credit both William Hick (1952) and Ray Hyman (1953), who independently arrived at similar formulations of the relationship between the number of stimuli and response time. In UX contexts, it is usually referred to as Hick's Law.
