THE EFFECT OF KNOWLEDGE REPRESENTATION SCHEMES ON MAINTAINABILITY OF KNOWLEDGE-BASED SYSTEMS

We use an experimental approach to investigate the representational ef fects of knowledge on maintainability, and compare this with the struc tural effects of rule sets investigated by Davis [5]. Results show tha t an object-based system, compared to a structured rule-based system, was easier to maintain in terms of the time to do the maintenance task s, but not necessarily in terms of accuracy of the alterations. Howeve r, in some instances subsumption and redundancies were introduced into the rule-based system, which can cause problems for subsequent mainte nance. Subjects perceived the structured rule-base system as more comp lex than the object-oriented system, and perceived the object structur e as more useful than the rule modularization and documentation.