Ontology-Driven Information Systems: Challenges and Requirements Burcu Yildiz 1 and Silvia Miksch 1,2 1 Institute for Software Technology and Interactive Systems, Vienna University of Technology, Vienna, Austria {yildiz, silvia}@ifs.tuwien.ac.at 2 Department of Information and Knowledge Engineering, Danube University Krems, Krems, Austria silvia.miksch@donau-uni.ac.at Abstract. The increased use of ontologies in several application fields makes it possible to observe requirements for their smooth integration within Information Systems. In this paper we analyse these requirements and propose the usage of additional semantic knowledge in the ontology to reconcile them. We think that these properties are essential to enhance the performance of ontology-driven Information Systems in general and ontology-driven Information Extraction Systems in particular. Keywords: Ontology, Ontology-driven Information Systems, Ontology-driven Information Extraction 1 Introduction Ontologies, being explicit specifications of conceptualisations (Gruber, 1993), can play a major role in many of todays Information Systems (ISs) as knowledge bearing artifacts. With regard to the impact an ontology can have on an IS, Guarino (Guarino, 1998) distinguishes between a temporal and a structural dimension. The temporal dimension describes whether an ontology is used at development time or at run-time, whereas the structural dimension describes in which way an ontology can affect the components of an IS (e.g., application programs, information resources, and user interfaces). In our work we focus on the temporal dimension, more precisely on the use of ontologies at run time. Using an ontology at run time can yield two forms of IS: ontology-aware IS and ontology-driven IS. An