Evidence for Learning: Reducing class size

Reducing class size

A summary of the research evidence on reducing class size in the Australasian context.

The Teaching & Learning Toolkit focuses on impact; it presents an estimate of the average impact of reducing class size on learning progress, based on the synthesis of a large number of quantitative studies from around the world.

This page offers a summary and analysis of individual Australasian studies on reducing class size. In contrast to the Toolkit it includes studies which do not estimate impact, but instead investigate the implementation of interventions and how they are perceived by school leaders, teachers and students. This information is valuable for school leaders and teachers interested in finding out more about particular examples of reducing class size interventions that have been delivered in Australia and New Zealand.

This Australasian Research Summary was generated by Melbourne Graduate School of Education in 2016. 

When used in isolation, the reduction of class sizes in Australian schools has little effect on student academic performance. Rather, pedagogy must also be transformed in association with smaller class size. Empirical studies confirm that students in the early primary years, and those who have unsatisfactory results, language backgrounds other than English, or low socio-economic backgrounds learn better in smaller classes. But, gifted students do not benefit from smaller class sizes. Nevertheless, there remains little research on how to instruct teachers to adapt their teaching practices for smaller class settings.

According to Hattie (2012), the effect size of reducing class sizes from 25 to 15 is 0.10−0.20. Because students are likely to learn better in small classes, increasing class sizes is not recommended. However, teaching in small classes needs to be reconceptualised if it is to be properly effective – the pedagogy needs to either change or improve, and this requires professional development (Hattie, 2012).

When class sizes are reduced, teachers often respond in one of three ways (Handal, Maher & Watson 2013). Based on a study of over 1000 teachers in 808 government schools in New South Wales, the first group, representing the majority of teachers, changed their teaching strategies when shifting to smaller classes, concentrating on individual development due to increased teacher-student interaction and reduced class management. The second group did not change their teaching strategies but were able to enhance the quality of their teaching strategies because of the fewer number of students. The third group used the same pedagogy for smaller classes as they did for larger classes, holding the view that their teaching practice was transferable across different class sizes (Handal et al., 2013).

Handal, Watson and Maher (2015) specifically examined teachers’ perceived impact of class size in a secondary mathematics context. Using mixed methods, they surveyed 83 secondary mathematics teachers and interviewed 12 of them. Their study had three key findings. First, mathematics teachers think reduced class size has a positive impact on learning, but this impact relies far more on teacher effectiveness and student competence. Second, low achieving students, students with language backgrounds other than English, and students from low socio-economic backgrounds are the principal beneficiaries of class size reduction, but this is not true for gifted and talented students. Third, students in the early years of education learn better in a small class.

Aligned to the second and third findings of Handal et al. (2015) above are the earlier findings of Zyngier (2014), which suggest that students in the early years of schooling, those from culturally, linguistically and economically disenfranchised backgrounds, and those in need of special learning support benefit from smaller classes. Zyngier’s (2014) paper synthesised 112 papers from 1979 – 2014, and its findings are reconfirmed by an experimental study of 63 schools in New South Wales whereby teachers were added to reduce class size. The study highlighted the important role of pedagogy in smaller classes to bring about improved student achievement, recommending the combination of class size reduction with teacher professional development programs.

In a (Chinese) second language-learning context, Chen and Yeung (2015) qualitatively studied the efficacy of teachers in relation to class size. Although learning a second language involves students in more group interactions, teachers with large classes were found to be less effective in implementing teaching and learning activities, communicating directly with individuals, and in involving every student. Teachers in small classes were more productive, as they had more time to monitor student progress, and provide prompt feedback and support.

Chen, Z., & Yeung, A. S. (2015). Self-efficacy in Teaching Chinese as a Foreign Language in Australian Schools. Australian Journal of Teacher Education, 40(8), 24 – 42.

Handal, B., Maher, M., & Watson, K. (2013). From large to small classes: A classroom window. Australasian Canadian Studies, 31(1/2), 53 – 72.

Handal, B., Watson, K., & Maher, M. (2015). Multi-positioning Mathematics Class Size: Teachers’ Views. International Journal for Mathematics Teaching and Learning, April 2015, 1 – 14.

Hattie, J. (2012). Visible Learning for Teachers: Maximizing Impact on Learning. London; New York: Routledge.

Zyngier, D. (2014). Class size and academic results, with a focus on children from culturally, linguistically and economically disenfranchised communities. Evidence Base, 1, 1 – 23.

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Class size reduction; classroom/​group size; class size groups; smaller classes.