"Minimal designer intervention" is not just nice, it is paramount. It can also be stated as minimal interference with the designer. The optimum interface would simply let the designers do what they do already      just write and draw anything they want during the course of the conceptual design process. Any additional SECONDS of participation required by the interface on the part of the designer during the working session must be jealously metered out. If the designer feels the interface gets in the way of doing design, it won't be used in actual practice.

The interface should not only be easy to use, but require NO designer participation at all to function at the lowest level. And any participation the designer does choose to donate must be handsomely rewarded; ie great payoff to the designer personally for small increments of increased participation. In particular we strove to avoid mandating the use of syntax driven menus in order to specify designs. Filling out forms is a valuable data entry technique in general, but often anoying during the conceptual design of mechanical artifacts.

There must also be minimal knowlege engineer participation      a goal of a few hours per month per designer.

Another criteria in the project was to accept the full richness of raw design notebooks as generated during design      that is, to let the designers create whatever text graphic information structures help them do design. And then during the map making, the system should deal with those aspects of that information that it can, but SAVE all the information to have it available for re processing again some time in the future (when we understand more about text graphics and design activity). This could be called a "text graphic based reasoning" approach, parallel to text based approaches, but including graphics.

A final criteria was upward compatibility with more traditional AI techniques. The global, raw text graphics first philosophy proposed here has certain advantages, but we also wanted at the same time to support in depth analysis of particular kinds of information in the notebook, as well as formal model based approaches to capturing design rationale. The ideal would be an integration of these various techniques      the use of in depth analysis and formal models would produce nicely mappable features, and at the same time design information maps would themselves be rich areas for application of analytic and formal methods.