The aim of this study was to discover whether or not different types of teaching style could be identified, and what effect they would have on pupils' development. Variables There were two separate projects. In the first, on teaching styles, about 900 3rd and 4th year primary school teachers, and the head teachers from their schools, answered questionnaires which were sent to them. The data eventually used for analysis was from 468 fourth year teachers' responses to questions about teaching methods and attitudes. Cluster analysis was used to identify teacher types from which typical teachers were chosen as the basis for the second project. In the second project, the classes of selected teachers were given various mathematics, reading, personality and behavioural tests at the beginning and the end of the academic year. A pupil typology was constructed, and it was attempted to relate this to performance, and performance changes, as well as to teaching style.