Collective design of an online math textbook: when individual and collective documentation works meet

This paper focuses on the documentation work in the mathematics teaching. We show up the individual and collective components of this documentation. We present a new theoretical framework, the documentational approach which seems adapted for studying this issue. We applied it on a particular project of the French teachers association S'esamath: the collective design of an online mathematics textbook. We present a methodology for observing both this collective project and the case of Ana"is, a teacher involved in this project. We study her professional interest in S'esamath, her didactical interactions with the other project members, and their effects on her professional knowledge.