Recent research designed to discover whether there is a correlation between the number of learners in a class and levels of attainment has produced conflicting findings. Common sense suggests that the smaller the class, the more time and attention the teacher will be able to devote to each individual learner, and therefore the more effective the learning. However, recent government‐funded research in the UK calls this assumption into question. For example, a study of pupil progress in over 200 primary schools conducted between 2002 and 2003 found that, although pupils aged 8–11 in larger classes receive less individual attention from the teacher, this has no measurable effect on their attainment in any subject, which is more likely to be affected by the economic circumstances of their home background, children from poorer homes making least progress. Similarly, a government‐funded review of international research into the effects of class size on pupil achievement concludes that it has less impact on learning than the level of skill and experience possessed by teachers.
Research carried out in America, on the other hand, suggests that small class sizes in the first four years of schooling can lead to higher attainment by the time the pupil reaches secondary education. A report in the Economic Journal (January 2001) on research carried out at Princeton University presented findings which showed that pupils taught in smaller classes during the primary phase of their education were more likely to go on eventually to apply for higher education, and that smaller classes were of particular benefit in raising the attainment of pupils from impoverished backgrounds and from minority groups. The positive impact of reduced class size on the learning of the very youngest pupils, particularly in literacy, is also reflected in a 2000 research report from the London Institute of Education, based on a study of 300 schools.
Class sizes in state schools in the UK, both primary and secondary, tend to be larger than those in other developed countries, and figures suggest no immediate trend towards reduction, having recently remained fairly static. For example, between 1996 and 2000 the average class size across all state schools was around 28 pupils to every teacher. Between 1985 and 2005, however, the average number of pupils in each class in the UK's fee‐paying schools fell from almost 14 pupils to 10. There is no statutory maximum class size beyond Key Stage 1 in the UK, except in Scotland, where there is an upper limit pledge of 18 pupils per class in primary 1 and primary 3. See also public school; pupil–teacher ratio.
P. Blatchford The Class Size Debate: Is Small Better? (Open University Press, 2003) explores both sides of the debate.