AbstractStudies of teacher effectiveness based in British secondary schools can be divided into four main categories: studies based on teachers' opinions regarding effective teaching, studies based on the relationship between rated teaching ability and other variables, studies based on observations of teaching and studies based on pupils' opinions regarding effective teaching. As a result of considering studies falling within these four categories, it is concluded that future research could most usefully concentrate on using rating scales based on observations of lessons within a design which looked at a particular subject area and allowed for differences in pupil age and ability.