Class Size Research project

The webpages describe results from a pioneering, independent research project of international significance, unique in its scale and methodology, and conducted by a large team at the Institute of Education, University of London.

The project aimed to study comprehensively for the first time in the UK the effect of class size and pupil/adult ratios upon pupils' academic attainment and on classroom processes such as teaching, pupil attention and classroom behaviour. The first section of the study examined the influence of class size from school entry in the reception year (4/5 years) through Key Stage 1 (5-7 years). The second stage of the study extended the project to an examination of Key Stage 2 (7-11 years). Both stages of the project are now complete.

The study offers an integrated account linking class size, classroom processes and academic attainment, and seeks to solve a long standing puzzle - why the view of professionals and parents that small classes provide a better quality of teaching and learning has not always been supported by research findings.

It identifies important implications for policy and practice, in terms of maximising opportunities of small classes and ways of minimising problems in large classes

The project was funded by the DfES (now DCSF), Local Authorities and the ESRC.

In a later study – the Deployment and Impact of Support Staff (DISS) project - we were able to examine the effects of class size on teacher pupil interaction and pupil classroom engagement across both primary and secondary sectors.

Some Publications you can access:

1. The most comprehensive description of the research, its background and a disussion of results is in the book:
Blatchford, P. (2003) The Class Size Debate: Is Small Better? Maidenhead: Open University Press

2. Main findings from the KS1 stage of the project (pupils aged 5-7 years can be found in: Blatchford, P., Bassett, P., Goldstein, H., and Martin. C. (2003) Are class size differences related to pupils’ educational progress and classroom processes? Findings from the Institute of Education Class Size Study of children aged 5-7 Years. British Educational Research Journal , 29, 5, 709-730. Special Issue ‘In Praise of Educational Research’, Guest Editors: S. Gorrard, C. Taylor and K. Roberts

3. Findings on the effect of class size and classroom processes when pupils aged 10/11 years: Blatchford, P., Bassett, P., and Brown, P. (2005) Teachers’ and pupils’ behaviour in large and small classes: a systematic observation study of pupils aged 10/11 years. Journal of Educational Psychology , 97,3, 454-467

4. Findings on the effects of class size on teaching can be found in: Blatchford, P., Russell, A., Bassett, P., Brown, P., and Martin, C. (2007) The effect of class size on the teaching of pupils aged 7-11 years. School Effectiveness and Improvement , 18, 2, June, 147-172

5. Some other recent findings will be be published in "Psychology of Classroom Learning: An Encyclopedia". These can be viewed by clicking here.

6. At the March 2008 American Educational Research Association Annual Meeting in New York Peter Blatchford presented new results on the connection between class size and student engagement and teacher pupil interactions. This was widely cited around the world. The paper by Peter Blatchford, Paul Bassett and Penelope Brown was titled: ‘Do low attaining and younger students benefit most from small classes? Results from a systematic observation study of class size effects on pupil classroom engagement and teacher pupil interaction’

Here is the Abstract:
It is now recognised by many that we need to know more about effects of class size on classroom interactions and pupil behaviour. This paper extends research in several ways:
a. it compares effects on two main types of behaviours – pupil classroom engagement and teacher to pupil interaction
b. it examines if effects vary by pupil attainment level
c. it examines effects of class size on classroom processes across the whole of the primary and secondary school years
d. it studies effects across the full range of class sizes found in UK schools
e. it uses systematic observation data to capture effects of class size on moment by moment behaviours and employs sophisticated multilevel statistical analyses that controls for possibly confounding factors and deals with the clustered nature of observation data within pupils and within classrooms within schools.

Results showed that as class sizes became smaller there were more times when pupils were the focus of a teacher’s attention, and more times when they were engaged in active interaction with teachers. This effect was found for all groups at both primary and secondary levels. It was also found that pupils’ classroom engagement decreased in larger classes and this problem was particularly marked for the pupils who are already attaining at lower levels. This, in turn, was accompanied by teachers seeking to control low attainers more than other groups in larger classes. It is suggested that small classes can be a valuable educational initiative right through school, but could be particularly targeted at lower attaining pupils at secondary level.

You can access the full paper by clicking here.