The knowledge communities as spaces hybrid involve, first, individuals who interact within a social network that produce content locally, and on the other hand, semantic entities, related within a semantic network with an autonomous structure. This thesis aims to explore the dynamics that drive social and semantic knowledge of these communities and their structural coupling. It relies primarily on two types of empirical objects: the scientific and the political blogosphere, which we follow the activity through in vivo observation of their finger marks. Our ambition is to achieve a realistic phenomenological reconstruction sociosémantiques dynamics of these communities of knowledge. To do this, we distinguish between the dynamics associated ...