Know Fitts’s Law

Fitts’s Law is a fundamental principle in human-computer interaction and ergonomics, formulated by psychologist Paul Fitts in 1954. It predicts the time it takes for a person to move to a target area (such as a button or link) based on two key factors:

The distance to the target
The size of the target

In simple terms, the closer and larger a target is, the easier and faster it is to click.

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Why It Matters in Design

Fitts’s Law is critical when designing interfaces that are fast, efficient, and user-friendly. It encourages designers to:

Place important buttons and links in easy-to-reach areas (like corners or screen edges)
Make interactive elements large enough to be easily tapped or clicked
Minimize unnecessary movement between frequently used controls

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Example in Practice

Think of a smartphone: the bottom navigation bar has large, easily tappable icons because thumbs can reach them quickly — a perfect application of Fitts’s Law.

By understanding and applying Fitts’s Law, designers can create interfaces that feel natural, responsive, and intuitive.

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