Education Endowment Foundation:EEF Blog: Grouping pupils by attainment – what does the evidence say?

EEF Blog: Grouping pupils by attainment – what does the evidence say?

Danielle Mason
Danielle Mason
Blog •6 minutes •

Whether and how to group pupils by attainment is something that schools and parents are particularly interested in. Practice varies across English schools with some grouping pupils by current attainment for some or all of their lessons; others grouping pupils by attainment within mixed classes; and some opting for fully mixed attainment teaching.

We regularly update our Teaching and Learning Toolkit both to incorporate the latest findings from robust educational research and to ensure that the evidence it summarises is communicated as accurately and clearly as possible.

Today we are updating one Toolkit entry (‘Setting or streaming’) and publishing a new Toolkit entry (‘Within-class attainment grouping’) in order to reflect better the existing evidence about the impact of grouping pupils by attainment.

Setting or streaming’

This updated Toolkit entry describes a variety of approaches by which pupils with similar levels of current attainment are consistently grouped together for lessons:

  • Setting’ usually involves grouping pupils in a given year-group into classes for specific subjects, such as English and mathematics, but not across the whole curriculum. 
  • Streaming’ involves grouping pupils into classes for all or most of their lessons, so that a pupil is in the same group regardless of the subject being taught. 

The aim of setting and streaming approaches is to enable more effective and efficient teaching by narrowing the range of pupil attainment in a class. In the UK, setting and streaming are more common in secondary school than in primary school.

Historically, our Toolkit entry on Setting or streaming’ encompassed a range of attainment grouping practices, including grouping pupils by attainment within mixed attainment classes, and grouping pupils by attainment across year groups

While these activities are sometimes referred to as setting’, the revised Toolkit entry adopts the narrower definition of setting or streaming’ described above, which we believe is a better reflection of what teachers in this country mean when they talk about the practice.

Within-class attainment grouping’

This new Toolkit entry focuses on approaches which organise pupils within their usual class for specific activities or topics, such as literacy. Pupils with similar levels of current attainment are grouped together – for example, on specific tables – but all pupils are taught by their usual teacher and support staff, and they usually all follow the same curriculum

The aim of this type of grouping is to match tasks, activities and support to pupils’ current capabilities, so that all pupils have an appropriate level of challenge. In the UK, within-class attainment grouping tends to be more common in primary schools than in secondary schools

The impact of attainment grouping

The overall impact estimate for Setting or streaming’ is ‑1 month’s attainment progress

Previously, the Toolkit analysis suggested that setting and streaming tended to be beneficial for high attaining pupils but detrimental for low attaining pupils. The new analysis, using the narrower definition, paints a similar picture, but with some important differences. First, the impact for high attaining pupils, while positive, appears to be very small. Second, for consistency with other strands we now present the headline average impact estimate for all pupils, which is negative. (For more detail on the previous Toolkit analysis you can read our blog here)

Interestingly, in contrast, the new Toolkit entry on Within-class attainment grouping’ shows a positive average attainment impact, equivalent to around +3 months of additional progress. The sub-group analysis suggests that this practice is beneficial for learners across the attainment range, although more so for higher performing pupils.

How secure is the evidence?

The evidence on attainment grouping has accumulated over at least 50 years and there are a large number of experimental studies. The conclusions are relatively consistent across different evidence reviews

However, most of the reviews present relatively basic analysis. They do not explore whether effects vary between different types of study and different interventions; the evidence base would benefit from new reviews which address these issues in more depth. The majority of the experimental evidence comes from the USA, and there are few rigorous experimental studies from other countries

Tightening the definition of Setting or streaming’ means there are fewer studies in the Toolkit analysis. As a result, the evidence rating for this entry has reduced from moderate’ (3 padlocks) to limited’ (2 padlocks) on the EEF’s 5‑point scale

The evidence for Within-class attainment grouping’ is also rated as limited’ (2 padlocks’)

This limited evidence base means there is a need for further good-quality research on attainment grouping. Today, the EEF is publishing the independent evaluations of two projects designed to investigate best practice approaches to grouping pupils by attainment. These highlight the challenges associated with trialling new grouping approaches, in terms of recruiting schools to take part and supporting them to adapt existing practices. Any future research will need to carefully take this into account.

The difference between Setting or streaming’ and Within-class attainment grouping’

Although the existing evidence base on attainment grouping is limited, what evidence there is suggests that within-class grouping is beneficial on average (+3 months) while setting or streaming is not (-1 month).

Yet both approaches aim to target teaching more effectively based on prior attainment, so what could account for this difference?

Here are six reasons we think are possible:

  1. Within-class attainment grouping is more likely to involve all pupils studying the same curriculum. This means that there is less risk of low or mid-range attaining pupils having their progress restricted by a less demanding curriculum or by not even being taught some of the content necessary for higher attainment. In contrast, setting or streaming can result in some pupils being allocated to a class where the content being taught is not sufficiently challenging – if the allocation process is not well designed, or if pupils develop more quickly than expected.
  2. Within-class attainment grouping tends to be a naturally more flexible approach. This makes it easier to re-assign to groups based on changing pupil needs. Again, this will reduce the risk that pupils remain in groups where the teaching content is not sufficiently challenging. Seeing more movement between groups may also reduce the risk of pupils losing confidence in their ability to learn and progress, which is a criticism sometimes made of setting or streaming.
  3. There is evidence that removing high-attainers from a class can have a detrimental impact on the progress of those left behind: within-class attainment grouping avoids this.
  4. Unlike setting or streaming, within-class attainment grouping also allows pupils of all attainment levels to be taught by the same class teacher. This removes the risk that teaching quality is reduced for the low attaining pupils, which can happen when the most experienced or well-qualified teachers are allocated to the top sets.
  5. It is also possible that being flexibly grouped within a mixed-attainment class has less negative impact on the confidence of low attaining pupils than being allocated permanently (or for a long period of time) to a low set or stream. On the other hand, it’s possible that finding themselves repeatedly on the low attaining’ table when grouped within a class could be just as detrimental for these pupils.
  6. Another possibility that we can’t rule out is that it is small-group work itself, rather than groupingby attainment, that is responsible for the additional benefit which within-class attainment grouping appears to deliver. Studies which measure the impact of within-class attainment grouping often compare it with mixed attainment whole-class teaching. This means it is possible that the positive impact is partly or wholly due to teaching in smaller groups, rather than to the fact that the groups are based on pupils’ prior attainment. This would be in line with what the evidence summarised in the Toolkit says about collaborative learning and small-group tuition. To know whether this is the case, we would need more high-quality studies which compare within-class attainment grouping with within-class grouping which is not based on attainment.


Here’s a three-point summary:

  • International evidence summarised in the EEF Toolkit suggests that within-class grouping is beneficial on average (+3 months) while setting or streaming is not (-1 month).
  • However, the evidence base is limited – we need more high-quality studies to test the impact on attainment of different practices.
  • Our Toolkit advises schools to think carefully about how to group pupils by attainment and to consider how the approach you choose will benefit pupils with different levels of prior attainment – in particular, low attaining pupils (disproportionately from disadvantaged backgrounds), who appear to be most at-risk of existing practices having a low or negative impact.