The relevance of didactic categories for analysing obstacles in conceptual change: Revisiting the case of multiplication of fractions

The theoretical framework of conceptual change has gained growing influence for analysing learning difficulties. The article pleads for combining conceptual change approaches in the learning sciences with established categories from mathematics education research, such as ‘Grundvorstellungen’ and epistemological obstacles. These didactic categories help to make explicit that obstacles in conceptual change can lie deeper in mathematical content knowledge than often seen in conceptual change approaches. The argumentation is developed by discussing the results of an empirical study of the well-known conception “multiplication makes bigger” and by integrating existing research into an explanatory level model.