On ambiguity and query-specific ontology mapping.

In the course of developing an ontology-based data integration system (OBDI) that includes automatic integration of data sources, and thus, includes algorithmic ontology mapping, we have made the following observations. A mapping method may determine that an entity in one ontology maps with equal likelihood to two or more entities in the other ontology. The mapping and reformulation of certain queries is correct only if one pairing is chosen. The correct choice may be different for different queries. Finally, the query itself may lend additional semantics that correctly resolve the ambiguity. These observations suggest a targeted ontology mapping problem, query-specific ontology mapping. In addition to the two ontologies, a query serves as a third argument to the mapping algorithm. Further, the mapping algorithm need not produce a complete mapping, but only a partial mapping sufficient to correctly reformulate the query. We detail a number of open issues on how this problem statement might be refined, and consider features of its evaluation.