In the French-speaking part of Switzerland, the kindergarten and the two first years of primary school form a single cycle (in this cycle, the pupils are between 4 and 8 years old). The transition from Kindergarten to primary school is not a new phenomenon, but this inevitable rupture must be accompanied (Clerc-Georgy & Kappeler, 2017) for pupils and teachers. In this context and with an aim of harmonising teaching and learning practices between these two levels, continuing training in form of a lesson study has been offered in a school. Over more than a year, three teams of kindergarten teachers, primary school teachers and facilitators met in two full LS cycle.
The objective of this paper is to understand how an LS system promotes the restructuring of teachers' professional beliefs and knowledge by focusing on the process of interaction between novice teachers, experienced teachers and facilitators. During this training research, 12 lesson preparations and 10 debriefings were filmed and transcribed. More specifically, our analysis model is based on the analysis of dialogical discussion spaces (Warwick & al., 2016 ; Vrikki & al. 2017) and types of professional knowledge by novie teachers, expert teachers and facilitators (Clerc-Georgy, 2013 ; Vanhulle, 2009).