Abstract
In the beginning of the Semantic Web, ontologies were usually constructed once by a single knowledge engineer and then used as a static conceptualization of some domain. Nowadays, knowledge bases are increasingly dynamically evolving and incorporate new knowledge from different heterogeneous domains -- some of which is even contributed by casual users (i.e., non-knowledge engineers) or even software agents. Given that ontologies are based on the rather strict formalism of Description Logics and their inference procedures, conflicts are likely to occur during ontology evolution. Conflicts, in turn, may cause an ontological knowledge base to become inconsistent and making reasoning impossible. Hence, every formalism for ontology evolution should provide a mechanism for resolving conflicts. In this paper we provide a general framework for conflict-free ontology evolution without changing the knowledge representation. Using a variant of Lehmann's Default Logics and Probabilistic Description Logics, we can invalidate unwanted implicit inferences without removing explicitly stated axioms. We show that this method outperforms classical ontology repair w.r.t. the amount of information lost while allowing for automatic conflict-solving when evolving ontologies.
Scharrenbach, T