Pupils' understanding of scientific evidence in the context of investigative work
The research reported in this study is based on a detailed observation study of pupils carrying out investigative work in primary and secondary schools. The thesis examines the question of the type and level of understanding of scientific evidence which is employed in a number of different types of tasks associated with two underlying substantive concepts. The results suggest that the characteristics of each task make different demands on pupils of different ages and show that some pupils, in both primary and secondary schools, are capable of applying and synthesising ideas about evidence effectively in a problem-solving situation. Most pupils, however, even in Year 9, show a weak understanding of the application of many of these ideas, such as repeatability, range and interval or the most appropriate type of graph. It is argued that if pupils are to understand scientific evidence, then these ideas need to be taught and their synthesis in investigative work regularly reinforced. The procedural understanding demonstrated by pupils in practical investigations is compared with the understanding revealed orally in an interview situation and in written tasks. While some pupils appear to use tacit understanding in practical tasks which cannot be accessed readily in other ways, the results also show that most pupils who can express ideas about evidence explicitly are more likely to apply and synthesise them in a problem-solving situation. It is likely that if ideas about evidence were taught explicitly, then the ability of pupils to apply and synthesise them in a problem-solving situation would improve. It is also argued that, because problem-solving skills are required by employers in science-based industry and because understanding evidence is important in everyday life, then these ideas need to be formally taught and assessed within science education.