Over-the-Shoulder Mode

The Over-the-Shoulder mode relies on the agent's monitoring of design activities. When a design misstep occurs, the user is notified immediately. This is analogous to the word processor continuously monitoring every keystroke or word, consulting with the dictionary, and alerting the instant a word is misspelled.

The Over-the-Shoulder mode can appear on the surface as constraint-enforced system. In addition to alerting the user to an invalid state of design, the invalid state could be immediately undone. As such, the precarious continuation of a fundamentally invalid design is avoided in much the same manner as a constraint system. However, the constraint-enforced mode may be based on a different model than the Over-the-Shoulder model. This mode would be the allowance of one solid object to move through another, but upon recognition of a constraint violation, the design state would immediately revert to the previous state where there was no such violation.