Currently dozens of XML-based applications exist or are under development. Many of them offer DTDs that define the structure of actual XML documents. Access to these documents relies on special purpose applications or on query languages that are closely tied to the document structures. Our approach uses ontologies to derive a canonical structure, i.e. a DTD, to access sets of distributed XML documents on a conceptual level.We will show how the combination of conceptual modeling, inheritance, and inference mechanisms on the one hand with the popularity, simplicity, and flexibility of XML on the other hand leads to applications providing a broad range of high quality information.

This paper presents an indexing methodology, based on semantic and syntactic information. This methodology will be integrated in a system for querying a base of documents from the Web for a limited domain. Hierarchical domain knowledge is used for indexing. The description logic CICLOP is the formalism used for representing the domain ontology. The ontology will be extended dynamically, due to DL inference capabilities. Syntactic knowledge is used in heuristics applied for query expansion into a Description logic representation. The CICLOP is the successor of the C3L project, which represented the collaboration with prof. Rembold from University of Karlsruhe and which is described in the Ph.D. dissertation of Thomas Kessel. Some modules of CICLOP were developped during the Diplomarbeit stage of Andrej Wagner and Ralf Kinzle from University of Karslruhe.