Perception-based mapping

The term refers to situations in which the operators need to examine the situation, but the examination is based on perception. The operators do not need to rely on remembering the recent activity. They can get it by perception of special signs.

Example

Typical text manipulation based on selection is perception-based, because the operators can perceive the selected text by special means (typically, grayed background).

Display aggregation

In order to ensure that the operators perceive the information required for proper mode mode (the mode on which the function depends), an indication of the relevant mode should be displayed close to the operator's focus of attention.

Example

In text editing, the focal point is at the cursor. If the Caps Lock state is indicated using a remote LED, the operators might miss it. A better indication, which the operators are more likely to notice, is by changing the cursor, to hint also on the keyboard mode.