I am presently the Senior Advisor on Strategic Academic Initiatives in the Office of the Provost, and a Professor in the Faculty of Education at York University, Toronto, Canada. From 2020 to 2023 I was the Vice-Provost, Academic and from 2016 to 2020 I served as the Dean of the Faculty of Education. Before coming to York in 2009 I held three previous academic appointments: Kingston University; University of British Columbia; University of East Anglia. I also worked as a Research Associate at Oxford University, where I obtained my D.Phil. and as a high school teacher of mathematics in the UK. My research is broadly situated in the field of mathematical thinking, learning, and teaching. More specifically I am interested in the notion of mathematical understanding – driven by the main question of what it might mean to understand a mathematical concept in different situations, and of how we might improve mathematics teaching to promote mathematical understanding. Current and recent projects include: the potential for theoretical frameworks of understanding as pedagogical tools; the nature of collective understanding (especially as an improvisational process); workplace mathematical learning and understanding; and students’ lived experiences of learning mathematics in schools