IOE - Faculty of Education and Society


New book explores the impact of class size on pupils and teachers

16 November 2020

Class size matters and large classes can have a negative impact on teaching and learning, a new book by UCL Institute of Education (IOE) Emeritus Professor Peter Blatchford and Dr Anthony Russell argues.

Primary children in lesson. Image: Phil Meech for UCL Institute of Education

The book, published by UCL Press, examines the complex relations involved in class sizes and the impact this has on pupil outcomes, teaching, peer relations, grouping practices and the administrative aspects of teaching, among many other key areas.

Some studies have shown that class size has little impact on pupils’ attainment. However, Professor Blatchford (Department of Psychology and Human Development) and Dr Russell state that the focus on class sizes has been exclusively on attainment in mathematics and a first language, and very little is known about the effects on other school subjects. Most importantly, they argue that the exclusive concern with effects on attainment risks underplaying other crucial factors that are impacted by class size.

The authors show in detail how large classes make differentiated teaching and individual support more difficult; make classroom management more demanding; increase the demands of marking, report writing, planning and preparation; and increase teacher stress.

They can also mean teachers have less knowledge about individual pupils, and reduce the amount of educationally valuable activities like practical and investigative tasks.

Large classes are also particularly demanding given the diverse pupil intake found in many UK schools. The researchers found that low attaining pupils and those with SEND are most disadvantaged in large classes. For example, at secondary level, low-attaining pupils tend to focus less on the lesson objectives as class sizes increase.

The book ‘Rethinking Class Size: The complex story of impact on teaching and learning’ draws on 20 years of systematic classroom observations, surveys of practitioners, detailed case studies and extensive reviews of research.

Professor Blatchford said: “Across the world we need to rethink the class size debate - and rethink research on class size. We do not need any more reviews of associations between class size and academic attainment. In order to reliably interpret the correlation between class size and attainment we have as researchers to understand what is going on in classrooms.

“Large classes can present profound problems for teaching, especially where there is wide diversity in pupil attainment levels.  In the book we develop a social pedagogical framework to account for the complex contextual, dynamic and relational factors at work.”

‘Rethinking Class Size: The complex story of impact on teaching and learning’ was published by UCL Press on 12 November 2020.



Image: Phil Meech for UCL Institute of Education