| 1984-1991 | Researcher at the Philipps-University of Marburg at the Department for Empirical Education |
| 1989-1992 | Freelance and full-time trainer in Human Ressource Development |
| 1993-1999 | Researcher at the Institute of Adult-Education at the University of Bremen |
| 2000-2004 | Head of department "Planning and Development" at the German Institute for Adult Education, Frankfurt/Bonn |
| SoSe 2002 | Stand-in professor for adult education at the Ruhr-University Bochum |
| Since July 2003 | Professor for Adult Education/Further Education at the Eberhard-Karls-University of Tübingen |
| Since 2012 | Academic Director of The German Institute for Adult Education – Leibniz Centre for Lifelong Learning (DIE) |