Abstract
In this paper we describe the principles of the design and development of an intelligent query interface, done in the context of the SEWASIE (SEmantic Webs and AgentS in Integrated Economies) European IST project. The SEWASIE project aims at enabling a uniform access to heterogeneous data sources through an integrated ontology. The query interface is meant to support a user in formulating a precise query - which best captures her/his information needs - even in the case of complete ignorance of the vocabulary of the underlying information system holding the data. The intelligence of the interface is driven by an ontology describing the domain of the data in the information system. The final purpose of the tool is to generate a conjunctive query ready to be executed by some evaluation engine associated to the information system.