Multi-layered approach to aligning heterogeneous ontologies

In various domain specific applications with heterogeneous databases, an ontologydriven approach to data integration relies on the alignment of the concepts of a global ontology that describes the domain, with the concepts of the ontologies that describe the data in the local databases. Once the alignment between the global ontology and each local ontology is established, agreements that encode a variety of mappings between concepts are derived. In this way, users can potentially query hundreds of distributed databases using a single query that hides the underlying heterogeneities. Using our approach, querying can be easily extended to new data sources. In this paper, we propose our “multi-layered” ontology alignment approach and the underlying algorithms that are used to establish mappings between the concepts. We also present the AgreementMaker, our ontology alignment tool that implements our approach, our tool displays the ontologies, supports several “mapping layers” visually, presents automatically generated mappings, and finally produces the agreements.