Abstract : This doctoral thesis is a descriptive mixed study which articulates both qualitative and quantitative data. In a heuristic goal for the study of the teaching practices by Bru and according to the works of Tardif and Lebrun on the teaching and learning paradigms, the research aims at identifying the homogeneity and heterogeneity aspects of distance teaching practices of a synchronic distance learning network, the Pyramide network. The framework allowing the data analysis of the research rests on three main axes: the teaching practices of a distance learning structure, the organizer of the teaching practices and the various approaches of e-learning. The hypothesis of the research is based on the cross study of these axes. The research protocol is based on a questionnaire, the scale of Likert and semi-structured interviews. The analysis of the quantitative data allowed the definition of key factors for homogeneity and heterogeneity of the practices through new organizers such as interaction, sense of mastering technological tools and pedagogic innovation within the Pyramide structure. The research confirms the hypothesis that the e-training practices are organized around thirty axes that we have defined following the analysis of the trainers' statements. However, it does not confirm the hypothesis that the Pyramid network is an organizer of homogeneity in spite of the strong character of the system which articulates structured pedagogic methods (AFT, TLP, TLT, visio) and an explicit pedagogic discourse rightfully centered on the learner in the teaching/learning situation. Overall, our research shows that pedagogic innovation is far from a reality in FOAD and that many teachers still favour the teaching paradigm over the learning paradigm.