Introduction to proof: the mediation of a dynamic software environment

ABSTRACT. This paper, which reports on a long-term teaching experiment carried out in the 9th and 10th grades of a scientific high school, is part of a larger co-ordinated research project. The work constitutes a ‘research for innovation’, in which action in the classroom is both a means and result of a study aimed at introducing pupils to theoretical thinking and at studying the ways in which this process is realised. The purpose of the study is to clarify the role of a particular software, Cabri-géomètre, in the teaching/learning process. Assuming a Vygotskian perspective, attention is focussed on the social construction of knowledge and on the semiotic mediation accomplished through cultural artefacts; the functioning of specific elements of the software will be described and analysed as instruments of semiotic mediation used by the teacher in classroom activities.