This research is concerned with investigating children's understanding of physical, chemical and biological changes while using an approach developed by the project Energy and Change. This project aimed to provide novel ways of teaching about the nature and direction of changes, in particular introducing ideas related to the Second Law of Thermodynamics in a way accessible to pupils aged I 1 upwards. To accomplish this, the project developed an abstract picture language
through which the scientific story is told. An intensive study of the learning of a number of different groups of pupils was undertaken, based on records of their written work, observational notes of lessons, and small group interviews. This paper follows the progress of three pairs of 12-year-old pupils over a period of eight months studying a variety of topics, drawing on the written assignments and tests they did, as well as on the observational records. The abstract picture
language and the teaching approach aim to provide a coherent and systematic account of the fundamental nature of all changes. The analysis reveals some of the issues which are involved in understanding the nature and causes of change and how this understanding can be fostered.