Recognition-based applications may have up to four states (READY,
LISTENING, RECOGNIZING, BLOCKED) but a minimum of two (LISTENING,
BLOCKED).
A spatial display is better than an multi-state indicator in a
single location.
Color coding is better than monochrome
Redundancy is best (e.g., using both location and color).
State indicators are by necessity placed outside or at the periphery
of the active task region, yet users need to monitor these. The above
suggestions increase the visual distinctiveness of the feedback
display and make it easier for the user to notice (peripherally) a
change in status.
