In this brief article I shall reflect first on the development of a theoretical model of knowledge elicitation and knowledge representation, derived from semiotic theory and from theatrical performance analysis (Hilton, 1989) and then on the application of some of these concepts in the MEDICA project, part of the European Commission AIM program. *These in mm lead to a possible schematization of a complementary three-stage development strategy for Al systems: (1) an expert system, (2) a cognitive support system, and (3) a reflective support system.