Can teachers be developed?

This article uses a simple analysis of the kinds of influences on the development of a teacher's pedagogical practice. It explores the effects of changes in policy, to consider whether there can be a single best practice. It draws upon a study of six primary school teachers' participation in a course for the development of their teaching of science. The main characteristics of these teachers' personal professional development are described and are related to the contexts and factors which probably contributed to their development. Proposals for an understanding of teachers' personal professional development as reflective rationality are offered. A comparison is made between this view and the current policies for teacher education and continuing professional development.