This article is part of an exploratory study to investigate empirically (N=429) the role of learners' active participation in computer-based discussion forums on their success in distance learning (DL). For this, we have chosen to study two criteria: the number of their connections to the computer platform and their actions on the forum. In this way, we have tried to target the structural and functional aspects of these forums. Thus, we will first highlight the major role of the discussion forum in the success of computer-based discussion forums (DF) on different levels from a literature review. Secondly, we will analyze the scores obtained by learners during a distance in-service training for teachers entitled "Communication in the classroom". We take the "FADEEP" online teaching platform as the field of investigation and target population the Moroccan teachers who have benefited from the said training. Finally, we conducted a series of interviews with the actors involved in the DL (N=20).