What is it?

Pupils with similar attainment levels are grouped together either for specific lessons on a regular basis (setting or regrouping) or as a class (streaming or tracking). The assumption is that it will be possible to teach more effectively or more efficiently with a narrower range of attainment in a class.

How effective is it?

The evidence consistently shows that while there may be some benefits for higher attaining pupils in particular subjects (with an average impact of one or two additional months progress for this group) these benefits are largely outweighed by the direct and indirect negative effects for mid-range and lower performing learners, with low attaining learners falling behind by on average one or two months a year compared with their progress in a class without segregation. In addition, research shows a clear longer term negative effect on the attitudes and engagement of low attaining and disadvantaged pupils. 

There is some evidence that effective and flexible grouping for particular tasks can be beneficial, or when high-performing teachers are assigned to low attaining groups. However, more routine setting arrangements tend to undermine low attainers’ confidence and the belief that effort is more important than ability. This is a clear example of what not to do if you want low-income pupils to benefit, as they are more likely to be assigned to lower attaining groups. Evidence suggests that the impact of setting is more detrimental to low attaining pupils in maths who do better in mixed attainment groups, and that ability grouping particularly affects upper primary and lower secondary education. The effects appear to be less clear-cut in other subjects, though negative effects are reported for low attaining pupils across the curriculum.

The clear exception to this overall finding is the impact of separate teaching for gifted and talented pupils, who benefit from a range of different kinds of ability grouping. These include ‘pull-out’ classes, accelerated classes and promotion (where pupils move up a year). The identification of gifted and talented pupils is a challenge and multiple criteria for assessment should be used. The effects of these programmes provide an advantage for these pupils of three and 12 months additional learning. 

It is important to note that gifted and talented learners may respond differently to certain teaching strategies compared to other students. For example they appear to benefit less from collaborative group work than other pupils, though this inference is based on only a limited number of studies. The most recent meta-analysis found smaller benefits for accelerated classes relative to those shown for pull out classes or promotion. Programmes which promote complex or higher order thinking appear to be most effective. Finally, it should be noted that the studies of gifted and talented programmes very rarely measure the impact of the schemes on other students. As with ability grouping more generally, care should be taken to ensure then these students do not feel “left behind”, or that their notion of the importance of effort is undermined. 

How secure is the evidence?

The evidence is robust and has accumulated over at least 30 years of research. Although there is some variation depending on methods and research design, conclusions on the impact of ability grouping are relatively consistent. International evidence, mostly from the USA, is consisted with a recent study conducted in the UK across 45 secondary schools. This study suggests that setting in maths may be a means of raising the attainment of higher attaining pupils in Years 7 to 9, but that the benefits for pupils in high performing groups come at the cost of reducing the attainment of lower attaining pupils, who make better progress in mixed ability classes.

What are the costs?

Ability grouping is an organisational strategy which has few, if any, financial costs associated with it.