When is inconsistency considered harmful: Temporal characterization of knowledge base inconsistency

Abstract

Real world inconsistent information often has to do with not only what conflicting circumstances are but also when they happen. In this paper we present our research work on the temporal characteristics of inconsistent information that can exist in an intelligent system. To facilitate the discussions, we use knowledge base (KB) to refer to the component in an intelligent system that contains knowledge about a problem domain. Knowledge in a KB can be represented in terms of different formalisms, and plays a pivotal role in how an intelligent system accomplishes its intended tasks. The main results reported in this paper include: (1) establishing a formal definition for temporal inconsistency for knowledge in a KB in terms of the interval temporal logic; (2) describing a systematic approach to identifying conflicting intervals for temporally inconsistent assertions in a KB; and (3) delineating the semantic difference between the classical and temporal inconsistency. © 2008 Springer Berlin Heidelberg.