A graph-based approach for resolving incoherent ontology mappings

Ontology mappings are regarded as the semantic bridges that link entities from different yet overlapping ontologies in order to support knowledge sharing and reuse on the Semantic Web. However, mappings can be wrong and result in logical conflicts among ontologies. Such kind of mappings are called incoherent mappings. As an important part of ontology matching, mapping validation aims at detecting the conflicts and restoring the coherence of mappings. In this paper, we propose a graph-based approach which is complete for detecting incoherent mappings among DL-Lite ontologies. The lightweight DL-Lite family of description logics stand out for tractable reasoning and efficient query answering capabilities. Our approach consists of a set of graph construction rules, a graph-based incoherence detection algorithm, and a graph-based incoherence repair algorithm. We propose and formalize three repair principles in an attempt to measure the wrong mappings, where the notion of common closures w.r.t. a mapping arc in the constructed graph is introduced. These principles feature a global removal strategy that is independent of individual ontology matchers. In order to relieve the loss of information among ontologies in the repair process, we further define a mapping revision operator so that common closures related to the removed mappings can be preserved in the graph. We implement the graph-based algorithms and evaluate their performance in a comparison with state-of-the-art systems on real-world ontologies. Experimental results show that our approach can remove more wrong mappings and achieve better repairing results in most of the cases.