This study assesses the meaning of light for 10-15 year old children. Data were gathered through interviews and questionnaires. Results indicate two different conceptions of light: light equated with its source, with its effects, or with a state; and light as a distinct entity, located in space between its source and the effect it produces. The majority of 10-11 year olds hold the first conception, whereas 13-14 year olds hold the second conception. It is up to teachers to assess where their students are in relation to the notion of light in space and adjust their instruction accordingly so students have a solid base for studying optics and can begin to understand light the way physicists do.
