Institutional positions
- Member of the boards of the European Society for Research in Mathematics Education(ERME)
- Acting head of the Centre for Higher Mathematics Education(Kompetenzzentrums Hochschuldidaktik Mathematik Kassel, khdm) (since 2016)
- Member of the board of the VeMINT-syndicate (Virtual Tutorium STEM)
- Head of the German Society for Mathematics Education (Gesellschaft für Didaktik der Mathematik, GDM) (2017-2021)
- Member of the board of the GDM (2010-2017) and since 2021
- Speaker of the study group stochastics (2006-2010)
- Pro-dean Departement Mathematics und Sciences, University of Kassel (2016-2019)
- Member of the board of the Center for Empirical Research on Learning and Instruction (Mitglied im Direktorium des Zentrums für Empirische Lehr-Lernforschung, ZELL) of the University of Kassel