International audienceIn this article, we note that an activity cannot be only defined by its effective form and knowledge of the field concerned which is brought into play. We propose to define an activity by knowledge of the field of training brought into play, by its form but also in what it can influence the state of knowledge of learning and the means that one has to check this impact. We propose here our results of multi-field research carried out around the specification and the modeling of teaching activities in the field of the reading with an aim of building an environment of follow-up of learning. We present the methodology of work practised in the team, the structure of the specifications of activities, the computational models ...