Best Practice in Mixed Attainment Grouping

The Best Practice in Mixed Attainment intervention provided training for schools to improve the effectiveness of teaching in mixed ability classes. 


Key Stage 3

Key stage


Cross curriculum


EEF Summary

How to group pupils is a key decision that every school has to make, and schools leaders need evidence on the impact of setting, streaming and mixed ability classes. We funded this pilot to see whether it is feasible to run a randomised controlled trial of mixed attainment grouping in maths and English classes.

The pilot struggled to recruit schools: any future trial would need to pay particular attention to the perceived risks and teacher workload associated with the transition to mixed ability teaching.

The teachers who did take part in the pilot found some of the mixed ability teaching practices challenging, but were positive about the perceived impacts, particularly on low attaining pupils. The outcome data collected did not show any overall improvement, but the pilot trial was small and not designed to measure the impact of the intervention.

This pilot – alongside another EEF trial on grouping practices – demonstrates the challenge of testing changes to grouping practices using a randomised controlled trial design. The EEF is exploring other methods that can be used to assess which grouping practices are most effective and why.

Research Results




Is there evidence to support the theory of change?


This pilot was designed to test the feasibility of a future trial, rather than to find evidence to support the theory of change.

Was the approach feasible?


Recruiting schools to the trial was challenging. However, participating schools did teach pupils in mixed ability classes and apply the differentiation and growth mindset techniques suggested during training.

Is the approach ready to be evaluated in a trial?


Should a future efficacy trial be considered, particular attention must be paid to eligibility criteria, clarity of expectations at recruitment and the teacher workload associated with implementing mixed attainment teaching.

Evaluation info





Key Stage

Key Stage 3

Start date

August 2014

End date

September 2018

Type of trial

Pilot Study

Evaluation Conclusions

  1. It was challenging to recruit and retain schools to the pilot trial. Despite directly contacting 158 schools and widely advertising the opportunity to another 330, only 18 agreed to be randomly allocated to either receive the training in mixed attainment grouping or to be a control group. 

  2. Staff had mixed experiences of the intervention; some enjoyed it, whereas others struggled, particularly with differentiation in mixed attainment groups. Schools that continued with the intervention generally adhered to the programme: allocating pupils to mixed attainment classes, applying differentiation techniques in the classroom, and communicating high expectations for all pupils. 

  3. Most interviewees felt that the intervention had a positive effect on pupil outcomes and that those with low prior attainment particularly benefitted. 

  4. The pilot RCT was small and designed to test whether a trial was possible rather than to measure the impact of the intervention. The outcome data that was collected did not show a difference in overall maths and English scores between intervention and control schools. 

  5. Should a future efficacy trial be considered, particular attention must be paid to eligibility criteria, clarity of expectations at recruitment and the teacher workload associated with implementing mixed attainment teaching.

  1. Updated: 7th March, 2019

    Printable project summary

    1 MB pdf - EEF-best-practice-in-mixed-attainment-grouping.pdf

  2. Updated: 6th September, 2018

    Evaluation report

    1 MB pdf - Intervention_B_-_Mixed_Attainment_Grouping.pdf

  3. Updated: 16th June, 2017

    Evaluation Protocol

    248 KB pdf - Round_6-EEFK_Intervention_B_Mixed_Attainment_Grouping_Amended_version.pdf

  4. Updated: 7th November, 2017

    Statistical Analysis Plan

    260 KB pdf - Round_6-_Ability_grouping_BPMA_SAP.pdf

Full project description

The Best Practice in Mixed Attainment (BPMA) intervention trained schools to adopt best practice mixed attainment approaches to grouping Year 7 and Year 8 students for English and mathematics in order to raise attainment. Schools were expected to create classes that contained pupils with a wide range of Key Stage 2 national curriculum results in English and mathematics. Teachers were trained to communicate high expectations of all pupils and to use flexible within class grouping and differentiation techniques. They were asked to minimise the use of marks levels and grades, and to provide formative feedback through comments instead, with a view to creating a growth mindset in pupils. The intervention was developed by a team now based at UCL Institute of Education.

The intervention was developed with three schools between September 2014 and July 2015 and piloted with a further eight intervention schools through a pilot randomised controlled trial (RCT) starting in September 2015 and following Year 7 students for two academic years. The trial was funded by the Education Endowment Foundation (EEF). The aim of the pilot trial was to help inform decisions about a future large-scale RCT and to identify barriers to adopting mixed ability teaching. Preliminary outcome data was collected in order to rehearse for a future trial.