The notion of certainty in the development of mathematics teacher educators' practices

Mathematics teacher educators’ (MTE) practices draw from experiences of learning to teach mathematics teachers. We use a self-study methodology to analyse one MTE’s experience designing and enacting instructional activities to support prospective teachers’ development of learning from teaching. Study data included critical friend conversations, MTE journals, and reflection on teaching. Critical friend conversations focused on developing one instructional activity served as data and an analytical tool. Analysis produced a description of the development of certainty in instructional activity design and implementation. We argue MTEs’ experiences of uncertainty and certainty inform instructional activity design and implementation in supporting PTs learning to teach mathematics.