Afholdt oplæg med titlen: AN ANALYSIS OF CONSEQUENCES OF DIDACTIC THEORY FOR PRACTICE – THE CASE OF MODELLING CYCLE Abstract: The teaching and learning of mathematical modelling is by now an established research area in mathematics education with theoretical developments, various approaches and empirical studies of various modelling activities in classrooms and their effects on students’ learning (e.g. Blum & Ferri, 2009). The modelling cycle and the notion of modelling competency are central constructs in several of these theoretical works on modelling in mathematics education. In upper secondary schools in Denmark mathematical modelling has entered into the curriculum and as a consequence also into textbooks where there are chapters on modelling featuring e.g. the modelling cycle from didactic theory. However, the modelling cycle is an analytic model of a mathematical modelling process. It is not a description of the practice of ‘real world’ modelling (e.g. see Frejd (2013)). We are interested in consequences of didactic theory for practice when the theory becomes part of the subject matter, so to speak. That is questions such as: What are the constraints of theory on practice? What does theory facilitate? What kind of practices has become common? Is there a more or less normative didactic setup, and if so, to what extent are common practices a consequence of such a setup? To be more specific, our research question for this presentation is the following: How does the didactic theory of modelling cycle affect the didactic practice, which constraints and conditions does it put on the teaching of mathematics? This will be investigated from the perspective of the Anthropological Theory of the Didactics (ATD) using the notion of didactic praxeology and didactic transposition (Bosch & Gascón, 2014). We will examine Danish curricula, exam exercises and different textbooks written by in-service teachers.