Abstract : The evolution of mobile technologies makes it now possible to use these technologies for collaborative work through web-based groupware systems. However, due to the limitations of these technologies and to the user's mobility, these systems must adapt the awareness information delivered to mobile users. In this work, we present an approach for adapting awareness information delivered to a mobile user, through a filtering mechanism which considers both the current context and preferences for this context. We propose an object-based representation for the notion of context, which takes into account the user's physical context as well as the user's collaborative context, which includes the notions of group, role, activity, etc. The user's preferences are represented by a set of profiles, which organize the delivered awareness information into several levels of detail. Finally, we propose a framework, named BW-M, which implements our proposition.