Gellof Kanselaar (1942) studied experimental psychology in Utrecht from 1966 to 1972. He graduated in 1983 with a thesis entitled "Cognitive Complexity".

From 1988 to 2006 he was full professor at the University of Utrecht in  the department of Educational Sciences, spec. in educational psychology and ICT in education. From 2006 to 2009 he was honorary professor and professor emeritus since then.

He was until his retirement research director of the ICO Isor. He led several research projects funded by NWO (Nat. Science Foundation), including in the field of collaborative learning with ICT (Computer Supported Collaborative Learning, CSCL), problem solving, computer applications in education in mathematics, physics and languages. He guided 16  PhD students as supervisor  and participated in more than 50 scientific publications since 2000.

He has held various management functions in national and international scientific organizations, including member of the Executive Board of the SVO, president of the National Association of Educational Research (VOR), member national management team, Research School ICO, organizer of master classes and international summer schools, member of committee Psychology of Education of the Belgian FWO until early 2005, member of organizing committees of national and international conferences, including the first European Conference on Computer Supported Collaborative Learning (Euro-CSCL), the CSCL conference in 2005 in Taiwan and the conference of the International Society of the Learning Sciences in 2008 in Utrecht, member of the evaluation commission of the Institut für Wissen Medien in Tübingen in February 2006, member of assessment panels to assess the quality of university programmes, e.g. Pedagogical and educational sciences in Flanders in 2006, Informatics and Computer Science in Flanders in 2010 and Psychology Universities in the Netherlands 2011-2012. Chair and member of assessment committees of the NRO/NWO in 2014.