Quantum theory plays a central role in the physics vision of the world and has to have its place in the school curriculum. Researches on how students learn quantum physics concepts evidenced the failure of traditional approaches in overcoming students difficulties, in the change from a classical point of view to a quantum one. Following research based proposal, developed at the University of Udine according to the Model of Educational Reconstruction. It aims to face students to quantum concepts and to build theoretic thinking, we carried out a study on the ways in which students learn quantum physics knots. The students learning paths from classical concept to the quantum one, reconstructed analyzing worksheet, pre-test and post-test, audio record of the school activities, evidenced a relevant role of ideas not well structured but coherent with alternative interpretation of quantum mechanics
