Year 12 students' mental models of the nature of light

This paper reports on the third year of a three-year longitudinal investigation into six Year 10 secondary students’ understanding of optics at a secondary school level. During the first two years of the study the students’ understanding of geometrical optics was explored with the adoption of constructivist teaching and learning strategies. The students' understanding of geometrical optics following the Year 11 teaching stage then formed the basis of exploration of their mental models of the nature of light. This exploration occurred before, during and following a Year 12 teaching stage where the students studied physical optics and quantum ideas. Before the Year 12 teaching stage the students had constructed mental models of light that related to their understanding of a ray. Over the Year 12 teaching stage the students’ mental models changed to conceptualizations of a photon. There was evidence in the students’ mental models of a hybridization of the particle and wave scientific models. That is, they conceptualized the photon as having both wave and particle characteristics. The variation in the students’ hybrid models also suggested a variation in the way they conceived of the nature of scientific models.