Teaching Optics: Light Sources and Shadows

The study of students representations of physics concepts and phenomena constitutes a central part of Physics Education research, as they play a critical role in teaching. In the study presented here, we investigate 120 ninth grade students mental representations of the formation of shadows. The empirical data was gathered through an interview using four tasks which involved the evaluation of hypothetical situations. The research data included representations that cause difficulty in the comprehension of the position of a light source in relevance to the shadow.