| 2011 - 2013 | Guest professor, ISV-Department of Social and Welfare Studies, Linköping University (Sweden) |
| 2006 - 2007 | Chair (W3) for Biology Education, University of Bremen |
| 2005 - 2006 | Founding Director of the Teacher Education Centre, Ludwig-Maximilians-University of Munich |
| 2004 - 2006 | Dean of the Faculty of Biology, Ludwig-Maximilians-University of Munich |
| 2000 - 2006 | Professor (C3) for Biology Education, Ludwig-Maximilians-University of Munich |
| 2000 | Offer of a Chair for Biology Education, Georg-August-University Göttingen (declined) |
| 1999 - 2000 | Research Scientist, Carl-von-Ossietzky University Oldenburg, Department Biology Education |
| 1995 - 1999 | Research Scientist, IPN – Leibniz Institute for Science and Mathematics Education, Department Biology Education, and Biology Teacher, Max-Planck-Gymnasium, Kiel |
| 1993 | Visiting Research Scientist, Institut de la Recherche Argonomique (INRA), Clermont-Ferrand (France) |
| 1993 - 1995 | Student Teacher, Studienseminar Stade (Lower Saxony) |
| 1990 - 1993 | Research Scientist, Kiel University, Botanical Institute |
