Complex matching based on competency questions for alignment: a first sketch.

Simple ontology alignments link a single entity of a source ontology to a single entity of a target ontology. Their lack of expressiveness can be overcome by complex alignments. This paper proposes a complex matching approach which relies on the notion of competency question for alignments (CQA). A CQA expresses the knowledge needs of an alignment in the form of questions the alignment must be able to cover. From a CQA translated into SPARQL and covering the source ontology, we limit the scope of the "pertinent part" of the source ontology and by consequence the scope of the alignment. From the reduced scope of the source ontology, we try to find the correspondences that express the source CQA with respect to the target ontology. Our approach has been evaluated on four knowledge bases about plant taxonomy.