摘要:The purpose of this study is to determine whether the knowledge structure of first level elementary school students for the ''light'' concept can be explained by "knowledge-as-theory perspective" or "knowledge-in-pieces perspective" and to contribute to the development of new teaching and learning techniques. In this research, clinical interview method was used. This method is a qualitative research method which aims to reveal what lies coginively behind the individual's explanations. In this study 21 fifth-grade students were selected and interviewed as participants. Students with similar level of success and Socio-ecomomic status, were choosen. A dark room was prepared in the same school where experimental activities were held and a set of clinical interviews were arranged. It was concluded that the knowledge structures about light concepts of students are suitable for "knowledge-in-pieces perspective" in theoretical concepts and "knowledge-as-theory perspective" for descriptive concepts.