Asking and answering semantic queries

One of the main issues in the development of the Semantic Web is the design and implementation of query languages that allow users to retrieve information from semantically annotated sources. In this paper, we describe a general methodology for querying a distributed collection of semantically heterogeneous resources, linked to each others through a collection of semantic mappings. The main contribution of this paper is the definition of semantic query, namely a query which enables users to tune a collection of semantic parameters to formulate the intended request. We show why this is different from what is typically done in data integration and peer-to-peer query reformulation.