Class Divides?: The impact of streaming on educational achievement and equality

Dr Michael Johnston
21 November, 2023

Classroom streaming – the separation of students into classes based on their prior attainment – is currently a topic of debate in New Zealand. Some commentators have called for the practice to be banned. The Ministry of Education would like schools to abandon it voluntarily.  

In this report, we examine New Zealand based and international evidence on the effects of streaming on students’ learning. The main findings were:

  • Greater gaps between higher and lower achieving students are commonly found in schools that stream than in schools that don’t. 

  • Increased educational inequality in streamed environments may be attributable to differences in teaching and curriculum rather than to streaming directly. 

  • Destreaming has its challenges. Unless appropriate changes to teaching practice accompany it, it can do more harm than good. 

  • The effects of streaming on students’ learning vary across subject areas. 

Research on streaming in the New Zealand context is almost entirely qualitative and based on small samples. There are very few New Zealand based studies that examine the effects of streaming on educational achievement. Most studies focus either on the streaming practices used by schools or on teachers’ and students’ views of streaming.

Read a two-page summary of our report here.


They talk about their research report on our podcast. Listen to that episode below:

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