aseline ognitive nalysis and esign, the distinctive system design method employed by entelics. The fundamental insight behind BCAD is that what matters most in the design of any system is the basic cognitive picture that people build as the result of their direct experience of that system. It is the structure of this basic cognitive map of the system that determines how people will understand, use, and participate in that system, much more than any specialized scientific or engineering knowledge employed in the design process, especially since most individuals involved with the system will lack the technical knowledge possessed by its designers.