Some issues regarding formal algebraic notation

We examine case studies (in progress) of teachers engaging with reflective practice on argumentation. The data comes from three sources i) audio taped meetings where all the teachers share their work with their colleagues, ii) videotaped lessons and iii) interviews of the teacher after each lesson. The aim is to identify the connection between the teachers' stated strategies and intentions (or 'espoused theories') and their 'theories-in-use' (what they actually do). The interviews and the group meetings enable the teachers to reflect on their practice and discuss their 'espoused theories' whereas the video taped lessons give us the opportunity to search for instances of their 'theories-in-use'. In this paper data from one case study will be presented and discussed.