ABSTRACT
My purpose in this chapter is to describe the process of conceptual development in the domain of astronomy and to discuss the kinds of instructional practices that can foster this development. I will argue that children form an intuitive understanding of the world according to which the earth is flat, stationary, and located in the middle of the universe; the sun and the moon move in an up/down or east/west direction and cause the day/night cycle; the stars are small objects; and gravity operates in an up/down gradient. These ideas change as children become exposed to current scientific views. The process of restructuring intuitive knowledge is a slow and gradual one and is characterized by the emergence of various misconceptions of scientific explanations. An analysis of students' misconceptions reveals that intuitive knowledge consists of a number of fundamental experiential beliefs and that understanding a scientific theory requires replacing these beliefs with a different explanatory framework. For instruction to be effective in bringing about conceptual change, we need to identify these experiential beliefs, to provide students with enough reasons to question them, and to offer a different explanatory framework to replace the one they already have.
