The user is able to predict how to use a control by its affordance.

Context

Apart from the classic click action, e.g., on a command button, controls have other ways of interacting with them, e.g., by dragging them.

Forces

Screen real estate is often an issue when trying to give controls a different shape.

Solution

Affordance can be conveyed using different methods, e.g., by:

• Giving controls a raised, 3D appearance.
• Adding texture to the control surface indicating its affordance.

Usability Impact

Error prevention, user satisfaction