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Plenįrias
INTRODUCING
PUPILS TO PROOF: THE MEDIATION OF CABRI
A teaching experiment has been carried out in the last years; it focused on introducing high school students' to proof. The main hypothesis we started with was that of providing a context where the idea of theory could develop, theoretical arguments and empirical data convinced us that the particular nature of the Cabri microworld could fit our needs. My contribution aims to present geometrical constructions in the Cabri environment as a specific "field of experience", within which the sense of theory may emerge. The theoretical meaning of geometrical construction is not spontaneous, but can emerge form the activities that pupils perform. The idea of construction evolves into the idea of theorem, passing through the need of justifying towards the idea of validating within a geometrical system. Protocols' analysis show the possible evolution of a justification into a proof as well as the fact that this evolution is not expected to be simple neither spontaneous. The specificity of the Cabri environment is determinant in order to make the sense of justification evolve from an empirical verification towards a theoretical proof |