Reference: Musen, M. A. Automated Support for Building and Extending Expert Models. 1989.
Abstract: Building a knowledge-based system is like developing a scientific theory. Although a knowledge base does not constitute a theory of some natural phenomenon, it does represent a theory of how a class of professionals approaches an application task. As when scientists develop a natural thoery, builders of expert systems first must formulate a model of the behavior that they wish to understand, and then must corroborate and extend that model with the aid of specific examples. There are thus two interreleated phases of knowledge-base construction: (1) model building and (2) model extension. Computer-based tools can assist devleopers with both phases of the knowledge- acquisition process. Workers in the area of knowledge acquisition have developed computer-based tools that emphasize either the building of new models or the extension of existing models. The PROTEGE knowledge-acquisition system addresses these two activities individually, and facilitates the construction of expert systems when the same general model can be applied to a variety of application tasks.