Abstract
Train students to take part in debates on Socio-Scientific Issues (SSI) has become a major concern. In this respect, computer-mediated debates provide new learning opportunities to carry out debates in classrooms. But what is precisely their contribution to help students develop argumentative skills on SSIs and grasp the complexity of these issues? In this study, we present and analyze the implementation of a teaching sequence in ten high school classes. This sequence is centered on a computer-mediated debate of which the starting point is a text and not a question. To assess the quality of argumentation and the structure of the debates, we developed an analysis grid based on a model of argumentation taking into account its dialogical and monological dimensions. Our analysis shows that a text-based computer-mediated debate helps students grasp and give rise to questions which are meaningful for them. It also allows them to tackle collectively and simultaneously the various dimensions of the SSI. However, we do not observe significant improvements of students' argumentative skills. In conclusion we discuss future directions of our work, concerning the teaching sequence and at the theoretical and methodological levels.