What does the research say about the impact of streaming, setting and attainment grouping on students?

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What does the research say about the impact of streaming, setting and attainment grouping on students?

By Nina Hood

Earlier this week a teacher wrote to me asking what the research says about the impact of streaming in schools. We have briefly touched on this issue in our resources on high expectation teaching, however, have never tackled it head on. Given the prevalence of some form of attainment grouping in New Zealand schools (this article touches on a number of different attainment[1] grouping practices– streaming, setting, banding and within-class grouping), exploring the research in this area seems a worthwhile undertaking[2]. For anyone concerned about educational inequality, what I uncovered in the research makes for some pretty grim reading.

Arguments for utilising some form of attainment grouping suggest that separating students into ‘ability’ or attainment groups enables teachers to stretch the most ‘able’ students and to support those who are ‘struggling’. While the rationale is understandable, the evidence suggests that grouping by attainment typically exacerbates inequalities in education rather than reducing them.

Overall, the evidence demonstrates that streaming or setting has little if any overall benefit in terms of student academic outcomes. Digging a bit deeper, the research suggests that while there may be small achievement gains for higher attaining students, the impact on students in lower attaining groups is negative. The evidence on within-class attainment grouping (a practice used most frequently in primary schools) similarly suggests that there is less benefit for lower attaining students, and that within-class attainment grouping is most successful if groups regularly change, students can move between groups, and that all students have opportunities to receive high quality instruction and to engage in rigorous tasks. Recent research found that in classes that utilise some form of attainment grouping, ‘low attaining learners fall behind by one or two months a year, on average, when compared with the progress of similar students in classes with mixed ability groups’, and that this effect is particularly strong in mathematics where setting is most common.[3]

Streaming and setting also have been found to have a negative impact on the social and emotional outcomes of many students. Research suggests that streaming can exacerbate the effect of socio-economic background on educational achievement, thereby reinforcing already existing social disadvantage experienced by certain groups of students. Furthermore, streaming often increases racial segregation within schools and there is evidence to suggest that streaming decreases students’ acceptance of racial difference and general positive interaction between racial groups. Streaming also has been shown to have a negative impact on the self-concept, confidence and motivation of students in lower streams, which in turn negatively impacts on their academic achievement and progress.

Streaming further disadvantages students from low-income families because the criteria and processes used to allocate students to different groups or streams are often problematic. In many instances, the allocation of students is not based solely on past academic achievement but also teachers’ perceptions of student behaviour and previous achievement. This finding is supported by recent New Zealand research, which showed that teacher judgments about student achievement in reading and writing were systematically lower for marginalised students after controlling for standardised achievement differences.[4]

The inequality of outcomes resulting from streaming or attainment grouping in part stems from the different ways that teachers work with higher and lower streams or groups. Teachers have been found to prefer teaching and to be more motivated when teaching higher attainment groups. Furthermore, teachers’ expectations of students in different groups differ significantly, which influences both the curriculum students in different groups access and the pedagogical practices teachers use. Students in lower ability groups typically receive a slower pace of instruction and less challenging work, which serves to enhance educational inequalities.

The prevalence of some form of streaming or attainment grouping in New Zealand schools can make it difficult for schools to think about whether and how to make a change. However, given the link between attainment grouping and increased educational inequalities, it is imperative that schools question their existing practices. The questions below may help to start the conversation in schools about the practice and impact of attainment grouping.

  1. Why do you use attainment groups? Do student outcomes (broadly conceptualised) suggest that your reasons for attainment grouping are justified?
  2. What does student achievement data show about the progress and attainment of students in different groups?
  3. Have you collected student voice to understand how grouping practices impact on the social and emotional learning and attitudes to learning of all students?
  4. How do teacher perceptions and expectations, pedagogical practices, and rigour of the curriculum differ when teaching different groups of students? How do you know this?
  5. How do you currently allocate students to groups? Have you assessed whether your grouping criteria could disadvantage certain students?
  6. How flexible are you in your grouping arrangements?

[1] Attainment is used rather than ability due to the literature suggesting that schools often confuse current (or recent) educational attainment with a notion of innate potential academic ‘ability’.

[2] This article has drawn on a range of research studies to inform the arguments made. See in particular: Higgins, S. et al. (2015). The Sutton Trust – Education Endowment Foundation Teaching and Learning Toolkit. London: Education Endowment Foundation; Johnston, O., & Wildy, H. (2016). The effects of streaming in the secondary school on learning outcomes for Australian students – A review of the international literature. Australian Journal of Education, 60 (1), 42-59. Taylor, B. et al. (2017). Factors deterring schools from mixed attainment teaching practice. Pedagogy, Culture & Society, 25 (3), 327-345; Taylor, B. et al. (2019). Why is it difficult for schools to establish equitable practices in allocating students to attainment ‘sets’? British Journal of Educational Studies, 67 (1), 5-24.

[3] Higgins, S. et al. (2015). The Sutton Trust – Education Endowment Foundation Teaching and Learning Toolkit. London: Education Endowment Foundation.

[4] Meissel, K. et al. (2016). Subjectivity of teacher judgments: Exploring student characteristics that influence teacher judgments of student ability. Teaching and Teacher Education, 65, 48-60.


Dr Nina Hood

Nina is responsible for the strategic direction and day-to-day operations of The Education Hub. She is a trained secondary school teacher, and taught at Epsom Girls Grammar and Mt Roskill Grammar in Auckland. She undertook an MSc (with distinction) in learning and technology, and a DPhil in Education at the University of Oxford. Since returning to New Zealand in mid-2015, Nina has been employed as a lecturer at the Faculty of Education at the University of Auckland, where she specialises in new technologies in education.

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