The aim of this text is to provide an account of the workshop that took place as part of the conference 'The Training of Mathematics Teachers between continuity and innovation: the Lesson Study', held in Turin in November 2022. This activity, aimed at secondary school teachers, focused on the observation phase in the context of Lesson Study (LS) training. More specifically, the aim of the workshop was to delve into this moment starting from the conception of the LS as a research process, and more precisely research-action. In the following pages, after briefly evoking the characteristics of LS and the points of contact with action-research, we review the activities carried out during the workshop. Finally, we present some concluding reflections on the LS process in general and the observation phase in particular.