Fitts's Law

The time it takes to move to a target is a function of the distance to the target and the size of the target. In other words, the larger an object is and the closer it is, the easier it is to use.

This law is particularly important in user interface design, especially for touch interfaces. To make interfaces more user-friendly, interactive elements should be:

• Large enough: Targets should be big enough for users to select them accurately without accidental misses.
• Well-spaced: There should be enough space between targets to prevent users from tapping the wrong one.
• Easily reachable: Targets should be placed in areas of the interface that are easy to reach. For example, on a mobile device, the most common actions should be placed within the thumb's reach.