‘Setting’ or ‘streaming’ refer to a variety of approaches by which students with similar levels of current achievement are consistently grouped together for lessons.

• ‘Setting’ usually involves grouping students in a given year group into classes for specific subjects, such as mathematics and English, but not across the whole curriculum.
• ‘Streaming’ (also known as ‘tracking’ in some countries) usually involves grouping students into classes for all or most of their lessons, so that a student is in the same group regardless of the subject being taught.

Students in different sets or streams sometimes follow a different curriculum, particularly when different national tests, different examination levels or different types of academic and vocational qualifications are available. The aim of setting and streaming approaches is to enable more effective and efficient teaching by narrowing the range of student achievement in a class.

Although these practices are sometimes described as ‘ability grouping’, we refer here to ‘achievement’ rather than ‘ability’, as schools generally use measures of current performance, rather than measures of ability, to group students. Setting and streaming are combined in this Toolkit entry because these practices are similar in that they separate students into whole classes of similar levels of achievement.

For evidence on the impact of grouping students by achievement within classes, see within class achievement grouping. Other types of achievement grouping, such as grouping by achievement across year groups, and teaching high achieving students with older year groups, are not covered in the Toolkit as they are less commonly used.

1. The impact of setting and streaming is 0 months progress, on average, with lower impacts for low achieving students. The evidence around setting and streaming is limited. Schools may consider other approaches to targeting learning effectively for students (e.g. small group or one to one tuition).

2. If schools choose to use setting and streaming it is vital to consider how the approach will enables more effective teaching for all students, including lower achieving students. For example, carefully considering how to allocate teachers appropriately to different sets.

3. It is important to ensure that all students follow a challenging curriculum, including lower achieving students. Ensuring flexibility in grouping arrangements, and regular monitoring of learning will minimise the risk of misallocation for students that learn at different rates.

4. Making informed choices about the allocation of students to groups is important. For example, there is some evidence of students being disadvantaged by their relative age within a year group or through subconscious bias on the basis of race or class.

On average, students experiencing setting or streaming make similar progress to students taught in mixed achievement classes. The evidence suggests that setting and streaming has a small negative impact on low achieving students, and a small positive impact for higher achieving students. There are exceptions to this pattern, with some variation between studies. Overall, the effects are negligible, and it appears that setting or streaming is not an effective way to raise achievement for most students.

Setting or streaming may also have an impact on wider outcomes such as confidence. Some studies from the broader evidence base conclude that grouping students on the basis of achievement may have longer term negative effects on the attitudes and engagement of low achieving students, for example, by discouraging the belief that their achievement can be improved through effort.

One of the challenges of achievement grouping is ensuring that students are correctly allocated to groups. Some studies from the UK suggest that misallocation is a particular problem for students from disadvantaged backgrounds, who are at greater risk of misallocation to lower achieving groups, and the negative impact which can accompany this.

The 2022 report Kōkirihia defines steaming as all practices that sort students into ability-based groups for sustained periods of time based on teacher perceptions of ability and assessment data. The report outlines a plan to move Aotearoa New Zealand schools away from these practices, with support from a range of education-sector peak bodies.

The impact on low achievers is typically lower than the impact overall. The average months progress is negative indicating that low achieving students in sets or streams make about 3 months less progress, on average, than similar students in classes with mixed achievement.

It should be noted that there is a very limited number of studies, most of which are old and that the effects do vary between studies. The age of the studies mean that this may not be representative of the efficacy of current setting and streaming approaches on student outcomes.

Despite these limitations, the evidence raises a risk of potential harm and it is, therefore, crucial that schools implementing setting and streaming carefully consider how they will mitigate the risk of negative impacts to low achieving students.

The average impact of setting on high achieving students is typically similar to, or slightly higher than, the impact on all students overall.

It should be noted that there is a very limited number of studies, most of which are old and that the effects do vary between studies.

The age of the studies mean that this may not be representative of the efficacy of current setting and streaming approaches on student outcomes.

Setting and streaming aims to improve student outcomes by ensuring that class content is well-targeted to student needs, and that students in lower achieving groups get appropriate support. Given the weakness of the evidence base, strong implementation will consider how to mitigate the potential risks of setting and streaming for low achieving students, it might include:

• Careful consideration of teacher allocation between sets to ensure that low achieving students receive high quality teaching
• The use of continued monitoring to ensure that students are in appropriate sets and are not misallocated
• Flexible practices that allow students to move between sets

Approaches to setting and streaming are typically delivered over the course of an academic year, with grouping often being informed by students’ achievement outcomes from the previous school year. Some schools may however move students between sets or streams during the school year.

Moving either from mixed ability grouping to setting and streaming or in the other direction is a substantial change that will need a careful implementation process. 

Grouping by achievement 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.