State Transparency

A common scene, repeated many times, finds a user who attempts to use a speech system, but nothing happens. It is not apparent to the user (or to others) what might be wrong. A well-designed speech interface should clearly and continuously indicate its state to the user. Do the following:

• Provide feedback to the user in the form of a graphic state display.
• Provide feedback about basic system parameters.
• If graphic feedback is impractical provide auditory feedback.
• Make users aware of long BLOCKED intervals, if such can be predicted.
• At all times, the user should know what can be spoken.
• Status displays must be rapidly interpretable, without detracting from the task-related activity.
• Do not overwhelm the user with feedback.