Differentiated instruction: an investigation into the effect of class compositional factors on teaching processes

Abstract Class composition factors including class size and the grade or other level of students are often studied for their impact on factors such as academic outcomes and student achievement, but less often address the impacts on teachers’ instructional strategies. This paper reports on an analysis of the relationship between class compositional factors, including class size and level of study, on differentiated instruction (DI) in the International Baccalaureate Diploma Programme (IBDP). In the IBDP, students take subjects at Standard Level (SL) or Higher Level (HL), and it is a common practice to combine classes of SL and HL students within each subject, often because enrolment numbers are too small to make streamed classes viable. Examining the practices of teachers in IBDP schools in Hong Kong, this paper outlines a typology of teachers’ approaches to DI, highlighting the ways compositional factors impact upon teaching and learning and reflecting on the relationship between teacher beliefs and actions in DI in their senior secondary classrooms.