This article has two objectives: first, to present some preliminary results of our research in which we focus on mapping young pupils' cognitive processes in geometry and on the process of knowledge transfer from an individual pupil to a group, i.e. on cognitive osmosis. The second objective is to demonstrate through own practice and experience how conducting experiments and engaging in their deep analysis can be an effective tool for the development of a teacher's professional competences.
The tool selected for the experiment is a set of geometrical problems from the learning environment of Cube buildings, involving 3D shapes and their 2D representations.