Abstract: CYC: A Case Study in Ontological Engineering

B. J. Copeland
University of Canterbury

Lenat's CYC is the severest test to date of the declarative paradigm of knowledge representation and of traditional AI's 'physical symbol system hypothesis'. Lenat and Guha describe CYC as 'mankind's first foray into large-scale ontological engineering'. In designing CYC Lenat and Guha have attempted to solve traditional philosophical problems in ontology, epistemology, and logic. This paper reviews four areas that have been extensively documented by Lenat and Guha: the problem of the nature of substance; the problem of causality; the frame problem; and the problem of reasoning within an inconsistent theory or set of beliefs. The solutions to these problems that Lenat and Guha offer turn out to be disappointingly weak. Lenat's prediction that he will produce 'a system with human-level breadth and depth of knowledge' by the early years of next century betrays a failure to appreciate the sheer difficulty of the ontological, logical and epistemological problems that he has taken on.