Is the earth flat or round? Knowledge acquisition in the domain of astronomy

Research into children's understanding of the earth and phenomena such as the gravity and the day-night cycle, is concerned with: the origins of children's knowledge; the content and structure of their concepts; and how scientific understanding is acquired. Two theories have been proposed to address the above issues in young children's pre-scientific understanding: 1) the mental model account (Vosniadou & Brewer, 1992, 1994) proposes that young children operate under the constraints of certain intuitive beliefs and construct consistent mental models of the earth; and 2) the fragmentation account (Nobes et al., 2003; Siegal et al., in press) proposes that young children's knowledge of the earth is a fragmented collection of ideas that lack coherence. The research presented in this thesis examines the content, structure and development of the earth knowledge in 4- to 11-year-olds. The key findings are that: 1) emerging knowledge of the earth consists of scientific ideas that co-exist without coherence; 2) knowledge progresses from fragmented to consistently scientific around the age of 8 years; 3) different methods - open questions and drawings vs. forced-choice questions and 3D model/picture selection - elicit different responses to questions about the earth, which explains the inconsistent findings between previous investigations; and 4) knowledge acquisition in astronomy does not take place in parallel with knowledge acquisition in biology. It is concluded that emerging knowledge in astronomy is a fragmented collection of ideas that are unified and coordinated through enrichment and enculturation in a domain-specific way. It is also suggested that different methods of testing can account for the discrepancies between the mental model and fragmentation accounts. Implications for our understanding of conceptual development in childhood are discussed