Proceedings of the Annual Meeting of the Cognitive Science Society

First, third, and fifth grade children were asked questions about the shape of the earth and about the day/night cycle. The majority of the children used a small number of well-defined mental models of the earth, the sun, and the m o o n to explain the day/night cycle. T h e younger children formed initial mental models which explained the day/night cycle in terms of everyday experience (e.g., the sun goes d o w n behind the mountains; clouds cover up the sun). T h e older children constructed synthetic mental models (e.g., the sun and m o o n revolve around the stationary earth every 24 hours; the earth rotates in an "up/down" direction with the sun and m o o n fixed at opposite sides) which are attempts to synthesize aspects of the scientific view with aspects of their initial models. A few of the older children appeared to have constmcted a mental model of the day/night cycle similar to the scientific one. The children's models of the shape of the earth provided strong "second-order" constraints on their models of the day/night cycle (e.g., children with flat earth models do not explain the day/night cycle in terms of the m o v e m e n t of the earth). The changes in the children's models with age was explained in terms of the gradual reinterpretation of a set of presuppositions, s o m e of which are present early in the child's life, and others which emerge later out of previously acquired knowledge.