Principle Four: Perceptible Information

The design communicates necessary information effectively to the user, regardless of ambient conditions or the user's sensory abilities.

Guidelines:

•  Use different modes (pictorial, verbal, tactile) for redundant presentation of essential information.

•  Provide adequate contrast between essential information and its surroundings.

•  Maximize "legibility" of essential information.

•  Differentiate elements in ways that can be described (i.e., make it easy to give instructions or directions).

•  Provide compatibility with a variety of techniques or devices used by people with sensory limitations.

Example: "talking" thermostat with large numerals