Pedagogic mediation of dynamic geometry in teachers' mathematical activities

Abstract

Dynamic geometry environments can support learning of geometry through meditating learners' activity. To understand how dynamic geometry environment mediate the activity of mathematics teachers, we used Rabardel's categories of instrument mediations in an instrument-mediated activity [1, 2]. We analyzed the discursive and inscriptive interactions of 4 mathematics teachers who worked for 15 weeks in a team to construct geometric figures and solve open-ended geometrical problems in a collaborative, dynamic geometry environment. In addition to Rabardel's epistemic and pragmatic mediations, we found and coined a third mediation-pedagogic mediation-by which teachers use the environment to help other team members understand particular geometric objects and relations among them.