Ludwigstraße 23, Gießen, Hesse, Germany
Graf studied at the University of Giessen. He worked there from 1992 to 2001.
Graf studied biology and geography at the University of Giessen from 1976 to 1983.
Graf began his career as a research fellow at Technische Universität Braunschweig. Then in 1989, he took a position of a deputy state chairman of German Life Sciences Association. Twelve years later Dittmar became a state chairman at that association. Also he served as a teacher of higher education at the Institute of Biology Didactics of the University of Giessen from 1992 to 2001.
In 2001, Dittmar was appointed a professor of the Department of Chemistry at TU Dortmund University. Since 2012 he has been a chairman of Biology Didactics Department at the University of Giessen. Dittmar is a professor of biology didactics at the University of Giessen.
Graf has been a member of the Science Council of the Society for the Scientific Investigation of Parasciences since 2008. Also he is a member of the editorial board of the journal "Zeitschrift für Didaktik der Biologie". Dittmar was a member of the executive board of the Department of Didactics of Biology at German Life Science Association from 2007 to 2009.
Graf is married to Doris Rehling.