Ontology-Based Integration of Information — A Survey of Existing Approaches

We review the use on ontologies for the integra- tion of heterogeneous information sources. Based on an in-depth evaluation of existing approaches to this problem we discuss how ontologies are used to support the integration task. We evaluate and compare the languages used to represent the ontolo- gies and the use of mappings between ontologies as well as to connect ontologies with information sources. We also enquire into ontology engineer- ing methods and tools used to develop ontologies for information integration. Based on the results of our analysis we summarize the state-of-the-art in ontology-based information integration and name areas of further research activities.