This paper describes the Electronic Schoolbag, a digital workspace developed at the University of Savoie (France) and analyses its usages. This online environment is dedicated to the educational world: it offers pupils, students, teachers, school staff, or parents, personal and group workspaces in which individual or collaborative activities can take place. The flexibility of this software, allowing synchronous or asynchronous activities, lies in the “participation model”. This model allows groups themselves to describe and organise their activities. The architecture that permits (...) its implementation in the Electronic Schoolbag workspace is described. The study of the practices of the workspace is then presented. This requires different observation methods, according to the different procedures chosen: real practices provided by quantitative methods (analysis of the logs of the actions and questionnaires) and imagined practices provided by qualitative methods (semi-directive interviews). The results obtained from the university users allow us to assess the evolution of the usages for different periods and on different university sites. The observatory also lets us list the main uses of the Electronic Schoolbag for educative communication (collaborative vs. individual, informative vs. communicative). (shrink)