7 - Knowledge Representation: The Knowledge Engineer as Epistemologist

Abstract

This chapter discusses the concept of knowledge representation. Knowledge representation is simply a way of organizing knowledge inside an expert system. Representation refers to the packaging, storage, and manipulation of knowledge in an expert system by methods called schemes. Just as the record and the relation are the schemes used in databases to package data, the frame, the rule, and their variations are the formats used in expert systems to bundle knowledge. Selecting the appropriate knowledge representation schemes to use in a given application is the first step in coding an expert system. The representation choices made at the start of a project influences tool selection, program performance, and the functionality of the system later on. However, choosing knowledge representation schemes need first not be a gruelingly painful process. In many cases, the schemes simply fall out at the start of the project. Certain schemes become obvious when the application and the users' needs are understood.