Representing Knowledge for Logic-Based Diagnosis.

Abstract

If one wants to use logic to build a diagnostic system, then it is not a matter of "just axiomatising" the domain; we have to understand how to use logic for diagnosis. We need some models of what diagnosis is, in order to be able to implement diagnostic systems. This paper considers 3 different "logical" definitions of diagnosis. Each of these are presented in a uniform framework of hypothetical reasoning where the user provides the possible hypotheses. These are compared as to the sort of knowledge that we need to provide them, and in their expressibilty. It seems as though there is no one framework which can claim to be the logical definition of diagnosis. Each of these approaches has been implemented in the Theorist system, and used on a number of domains. This paper concentrates on the case where we have fault models.