Using Description Logics for Ontology Extraction

The paper presents a prototype of a system for querying the Web in natural language (French) for a limited domain. The domain knowledge, represented in description logics (DL), is used for filtering the results of the search and is extended dynamically, (when new concepts are identified in the texts) as result of DL inference mechanisms. The conceptual hierarchy is built semi-automatically from the texts. Different small French corpora (heart surgery, newspaper articles, papers on natural language processing) have been used for experimenting the prototype. The system uses shallow natural language parsing techniques and DL reasoning mechanisms are used to handle incomplete or incorrect user queries.