The present study aims to compare how Piaget and Vygotsky theories promote conceptual change in children’s scientific thinking. The investigation is an adaptation of a procedure used in 1930 by Piaget and compares two children’s predictions and explanations of why some objects float or sink. Children’s thinking is then challenged using discovery learning and scaffolding with the aim to investigate how each approach promotes a shift in their scientific thinking. Their explanations are coded, quantified and compared. The findings support Piaget stage theory and although scaffolding approach proved more effective, both approaches can be considered complementary. Word count: 96
Scientific knowledge is not only the accumulation of facts and procedures, it is more a way of thinking, is generative, allowing people to explain things that they have never been taught (Nunes and Bryant, 2004, p.267-8). However, to understand scientific concepts, Inhelder and Piaget (1958, cited in Nunes and Bryant, p.288) suggested that children need to attain a certain cognitive development, considering that this occurs at the formal operational stage (of development).
Common-sense understanding of concepts differs from scientific understanding. Contrary to ordinary people, scientists strive for consistency and aspire to use as few postulates as possible to explain as many phenomena as possible (parsimony principle). In the specific case of floating and sinking the naïve and especially young children conception, stressed by Selley (1993) too, is that objects sink because they are heavy, or because of the material they are made of (hypothesis 1=H1). When they realise that this hypothesis is not sufficient to explain floating or sinking, they extend the explanation to the objects’ air content. Progressing in thinking makes children think about the relationship between weight and size (mass and volume), shifting to hypothesis 2 (H2). Further progress makes them relinquish hypothesis 2 for hypothesis 3 (H3) and so on.
Changing the ways of thinking supposes conceptual changes. It is not enough that the teacher tells students how scientists think and that they learn definitions and formulae (Nunes and Bryant, 2004, p.290-1). Piaget hypothesized that conceptual change is produced when conflict occurs in pupils understanding, creating disequilibrium in their ways of thinking. As a result, new equilibrium cognitive processes are created which eventually promote the conceptual change (Nunes and Bryant, 2004, p.291). The teacher should select the challenging situation and the pupils should be actively involved in solving problems if they were to develop scientific thinking (discovery learning). However, he admitted that contradictory evidence is not enough for young children to give up their ‘theories’. Subsequent research, like that conducted by Howe et al. (1991, 1992, cited in Nunes and Bryant, 2004, p.292-3) revealed the important role of the interpersonal conflict and discussions (with peers) in the promotion of the conceptual change (collaborative learning). Vygotsky suggested that not only children’s own involvement, but also their interactions in the social world produce conceptual change. To explain the social nature of the conceptual change he developed the concept of zone of proximal development, which is the difference between what children can achieve by themselves and what they can achieve with the help of adults (learning as appropriation) (Nunes and Bryant, 2004, p.293-4).
The purpose of this investigation is to see on what basis children make predictions about objects’ buoyancy, how they construct theories about floating and sinking and what makes them to discard one hypothesis for another, what produces a shift in their thinking. Word count: 465
This study was a...