Researcher, Max Planck Institute Educational Research, Berlin, 1965-1969. Habilitatus research scholar German Research Association, Bonn, 1969-1970. Professor economics of education Technology University Berlin, 1971-1974.
Head research group German Institute Economics, Berlin, 1972-1975. Professor economics of education University Bielefeld, since 1974. Consultant for vocational training research Federal German Ministry of Labor, 1969-1970.
Consultant vocational training research Federal Institute Voc. Education, Berlin, Bonn, 1971-1981. Instructor vocational training and financing In German Foundation for International Development, since 1983.