RATIONALE

"Rutgers, VEXED"

L. I. Steinberg, Design as Top-Down Refinement Plus Constraint
Propagation. In: Artificial Intelligence in Engineering Design,
Vol. 1, (Eds) C. Tong & D. Sriram, Academic Press, 1992, pp. 251-272.  


The VEXED system incorporates a model of designing that is based on
top-down refinement and constraint propagation at every step.

Refinement is controlled by refinement/decomposition rules
presented by the system with the user selecting the one to use: as
such it is a cooperative system, with user and system sharing the
work.  Contraint propagation detects whether inputs and outputs match
given the design choices.  

It raises the issue of the importance of user interaction in
computational design systems, as well as that of good interface
design.