Noting that expert computer systems respond to various contexts in terms of knowledge representation, this paper explains that heuristic rules of production, procedural representation, and frame representation have been adapted to such areas as medical diagnosis, signal interpretation, design and planning of electrical circuits and computer system configurations, data analysis in protein crystallography and geology, and expert system construction itself. The paper goes on to examine production rules--procedural and frame representations in the development of an expert system that can analyze syntactic and semantic patterns in written discourse. It is observed that case grammar analysis and semantic differential scale techniques, encoded into a computer program called BOSS, generate textual analysis. Finally, ways an expert system can be used in a writing classroom are discussed. (Author/HOD)