The case of Cabri-géomètre: learning geometry in a computer based environment

One of the reasons teachers may resist the use of computers in the mathematics classrooms is the change that this introduction implies about the kind of problems fostering the acquisition of knowledge by the pupil. Some old problems become uninteresting in the new environment. Conversely computers allow the design of some new problems that are impossible in a paper and pencil environment. In our paper we consider the computer as part of the “milieu didactique” : as such it offers specific representations of knowledge, specific facilities and specific feedback to the pupils. We will discuss the role of these characteristics on the way mathematical objects may be perceived on the interface by the pupils and on the solving processes of the pupils when they are confronted to problem situations on the computer, using the geometry program Cabri-geometre.