Quantum Physics 337 LEARNING PATHS OF HIGH SCHOOL STUDENTS IN QUANTUM MECHANICS Marisa Michelini 1, ) a , Alberto Stefanel 1 1 Research Unit in Physics Education, Physics Dep. University of Udine, Italy 1 INTRODUCTION As far as the way students face and learn quantum physics is concerned, three main aspects, producing learning problems, are considered in literature: a) the different ontological status of quantum systems with respect to classical ones [1,2,3]; b) disciplinary knots, i.e. concept of state, its formal representation, meaning of eigenvalue [4;5,6], impossibility to associate a trajectory to a quantum system [4;7]; c) use of semiclassical models [1,8-10]. The analysis of learning difficulties is often correlated to the effectiveness of innovative instructional strategies in producing a well defined quantum vision of systems and processes [4,9-11]. The opportunity to analyse developed ideas and the interpretative conceptions build by students is partially lost. A teaching-learning proposal about Quantum Mechanics (QM hereafter), developed starting from the phenomenology of photons polarization, which aims at building the theoretical thinking favouring the formulation of interpretative hypotheses by pupils to be compared with the results of defined experiment- problems [12-14], allowed four different studies [15-18]. The results suggested that several students approach quantum ideas starting from deep-rooted, often implicit deterministic conceptions of nature, rather than from a coherent classical vision. Moreover, they develop conceptions recalling a local hidden variables description of phenomena, rather than a QM standard ones [17,18]. To acquire information about how students change from classic thinking to a quantum one, we carried out the study here presented and based on the following research questions: R1) which reasoning students follow in the conceptual reflections? R2) which elements favour the elaboration of new interpretative ideas? R3) which are the conceptual schemes of reference: classical, quantum, hidden variables ones? 2 THE CONTEXT This study was in a last year class of a High School with 18-19 years old pupils (21 females-1 male). Our sample is composed by the 18 students always present in the several activities, listed in the work plan shown in Table 1. During the 1 st and the last hours the students filled the pre/post test. In hours 2-4 th the students face on the light polarization phenomena, to acquire confidence about the situations re- examined in hours 5-9 th , aim to build quantum concepts exploring ideal case of single photon and polaroids/birefringent crystals interaction. All activities were ⎯⎯⎯⎯⎯⎯ a) Corresponding author’s e-mail: michelini@fisica.uniud.it