Abstract
This report discusses university physics students’ conceptualizations of the factors affecting the speed of sound propagation. The data source consists of a set of detailed explanations which Canadian and South African physics graduates provided during the course of clinical‐like interviews dealing with their understanding of sound. The analysis of the students’ explanations was set in the phenomenographic tradition: their categorization led to the characterization of three qualitatively different conceptualizations. The conceptualizations are illustrated with dialogue excerpts taken from the student interviews. Implications for physics teaching are discussed.