I studied computer science and economics at the University of Kaiserslautern and received the Diplom (master's degree) in 1996. Since then, I am working as a research scientist at the German Research Center for Artificial Intelligence (DFKI GmbH) Kaiserslautern. In the research department for Intelligent Engineering Systems I investigated in the VEGA project logic programming and machine learning approaches for the maintenance of knowledge-bases. In 2000 and 2001, I was project leader of the FRODO project (DFKI Knowledge Management Group) where we develop a framework for building distributed organizational memories. As a visiting researcher at theStanford Medical Informatics department (August - October 1999 and November 2000 - February 2001) I developed various plugins for the the frame-based knowledge acquisition tool Protégé-2000, incl. the OntoViz ontology visualization tab and the RDFS and OIL backends. In 2002, I was a visiting researcher at the Stanford Database Group and at ISI, working on the Edutella project and the Semantic Web rule language TRIPLE. Currently, I'm cohead of the Competence Center Semantic Web (CCSW) at DFKI.