“…As ontologies have gained growing attention over the past decade, many people have used an ontology as the global schema for a data integration system, building socalled ontology-based information integration systems, for example, Carnot (Collet, Huhns, & Shen, 1991), SIMS (Arens, Knoblock, & Shen, 1996), OBSERVER (Mena, Illarramendi, Kashyap, & Sheth, 1996), Information Manifold (Levy, Srivastava, & Kirk, 1996), InfoSleuth (Bayardo et al, 1997), PICSEL (Goasdoue, Lattes, & Rousset, 1999), and DWQ (Calvanese, Giacomo, Lenzerini, Nardi, & Rosati, 2001). In these systems, mappings are specified from data sources to an ontology acting as a global schema.…”