Advancement of In-Service Teacher’s Pedagogical Content Knowledge When Teaching Mathematical Modelling: Through the Interpretation and Design of Modelling Lessons

Mathematics teachers are required to acquire modelling-specific pedagogical content knowledge (MsPCK) to enhance their modelling teaching. We conducted a teacher training where one teacher interpreted and redesigned their modelling lesson, with support from the teacher educator. This training followed the ALACT model, a cyclical process of action and reflection by the teacher known as. This chapter clarifies how an in-service teacher’s MsPCK advances through the activities of interpreting and designing their own modelling lessons. Three findings are identified: (1) aspects of the teacher’s advances in MsPCK; (2) the importance of the teacher educator providing the theoretical framework to the teacher at the right time; and (3) the value of accurate teacher educator support for the teacher in response to the teacher’s activities.