Setting or streaming

Negative impact for very low or no cost, based on moderate evidence.

Cost Per Pupil Cost estimate: Less than £80 per pupil per year. cost per pupil
Evidence Rating Evidence estimate: Two or more rigorous meta-analyses. evidence rating Average impact: - 1 month. Impact -1 month

What is it?

Pupils with similar levels of current attainment are grouped together either for specific lessons on a regular basis (setting or regrouping) or as a whole 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?

Overall, ability grouping appears to benefit higher attaining pupils and be detrimental to the learning of mid-range and lower attaining learners. On average, ability grouping does not appear to be an effective strategy for raising the attainment of disadvantaged pupils, who are more likely to be assigned to lower groups. Summer born pupils and students from ethnic minority backgrounds are also likely to be adversely affected by ability grouping.

On average, studies show that higher attaining learners make between one and two additional months progress when set or streamed compared to when taught in mixed ability groups. Studies of targeted interventions for pupils identified as “gifted and talented” are consistent with this finding. They show that high attaining pupils benefit from a range of different kinds of ability grouping including pull-out classes, accelerated classes and promotion (where high attaining pupils move up a year). The effects of these programmes potentially provide an advantage for these pupils of three and 12 months additional learning. However, research into gifted and talented schemes rarely records the impact of the schemes on the students not identified as gifted and talented, who are more likely to be from disadvantaged backgrounds.

Low attaining learners fall behind by one or two months a year, on average, when compared with the progress of similar students in classes without ability grouping. It appears likely that routine setting or streaming arrangements undermine low attainers’ confidence and discourage the belief that attainment can be improved through effort. Research also suggests that ability grouping can have a longer term negative effect on the attitudes and engagement of low attaining pupils. It should be noted that there are some exceptions to this average, where ability grouping has benefitted all learners. Further study could be undertaken to understand what happened differently in these examples.

Evidence suggests that the impact of setting is more detrimental to low attaining pupils in mathematics 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.

Though the average impact of ability grouping on low attaining pupils is negative, evidence suggests that certain types of ability grouping are more effective than others. Some studies have shown that reducing the size of the lowest attaining groups and assigning high-performing teachers to these groups can be effective, as can providing additional targeted catch up support.

How secure is the evidence?

The evidence on ability is fairly consistent 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. 

Though much of the research into mixed ability grouping is dated and based on studies from overseas, a recent study conducted across 45 secondary schools in the UK showed a similar effect to previous research. This study suggests that setting in mathematics 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. Overall the evidence is estimated as moderate.

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What are the costs?

Ability grouping is an organisational strategy which has few, if any, financial costs associated with it. Additional resources may be needed to support different groups. Overall the costs are estimated as very low.

What should I consider?

  • Flexible within-class grouping is preferable to tracking or streaming for low attaining pupils.

  • The key issue is ensuring that any ability grouping benefits all learners, particularly low-attaining or disadvantaged pupils, over both the long and short term.

  • It is important to recognise that a measure of current attainment, such as a recent curriculum test, is not the same as a measure of ability or of potential.

  • Have you considered how the differences in grouping will enable more effective teaching for all pupils, including lower attaining pupils?

  • How will you monitor the impact of ability grouping on pupils’ attitudes to learning and their engagement?