Models: toward integrated knowledge modeling environments

Abstract

Building knowledge-based problem solvers requires an intellectually challenging modeling stage whose dominance over other activities is now widely recognized. In spite of this, current languages and environments leave the modeling activity on the shoulders of the human, concentrating on the routine programming aspect. Next generation languages and tools will have to explicitly support modeling in the first place. This paper presents a proposal for such a next generation knowledge modeling environment and discusses some steps we have made in this direction. Unlike existing programming environments, knowledge modeling environments focus on manipulating explicit, declarative specifications of problem-solving models which must be acquired, organized, modified, explained, validated, simulated and, eventually, translated into performance computer languages. Programming is only one of the activities supported in such an environment. This paper also discusses the knowledge modeling language we have developed as the foundation of the modeling environment. This language extends term classification technology with refinement, constraints, patterns and events, actions and methods, in order to support the description of both domain and control specifications required by problem-solving models. To substantiate the claims about the adequacy of the language, the paper presents two important modeling applications. The first is developing a full KADS language on top of it and the second is modeling a well known generic problem solving method, "propose-and-revise".