The Class Size Enigma

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John Dabell

I trained as a primary school teacher 25 years ago, starting my career in London and then I taught in a range of schools in the Midlands. In between teaching jobs, I worked as an Ofsted inspector (no hate mail please!), national in-service provider, project...
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Does class size matter?

Yes, that old chestnut. It’s been a fail-safe political football for years that often goes flat for a while until someone pumps it up again and starts booting it around. The forthcoming election is a good time to give it a good kicking and it’s already caused an own goal for the opposition.

According to Labour, class size matters a great deal. Jeremy Corbyn recently said that too many children were “crammed into classrooms like sardines” due to Tory education cuts. He has pledged that Labour will keep class sizes down and reduce class sizes to under 30 for all five, six and seven year olds.

Substantial Car Crash

But how many children are we talking about in super-size classrooms of 31 or more? 50, 5000, 5 million?

LBC presenter Nick Ferrari had to ask Shadow Education Secretary Angela Rayner MP this question four times but she was unable to answer refusing to “pluck a number out of thin air”.

Nick ended up providing her with the figure she should have known and quoted there were 520,445 children – Labour later made clear that the figure was 538,254 children.

When the wheels come off, they usually detach themselves in pretty spectacular fashion. Politicians tripping themselves up and getting in a muddle with their figures is nothing new and neither is the class size ‘debate’.

The Facts

Hundreds of thousands of children are in overcrowded classrooms but as Full Fact, the UK’s Independent Fact Checking charity, note,

“Hundreds of thousands of children were in classes of more than 30 last year. That’s been true for at least the last decade, although it’s become more common to have large primary school classes recently.”


Image result for class sizes under the conservatives full fact


Image: Full Fact

Have class sizes soared under the Conservatives? Full Fact report,

“The average class size in English state primary schools has been increasing. It rose from 26.4 pupils in 2010 to 27.1 in 2016. In secondary schools, average class sizes have dropped from 20.5 to 20.4 in the same period.


Image result for primary class sizes in england and wales full fact


Image: Full Fact

Know Thy Impact

The UK might have some of the biggest class sizes in the developed world but does that really matter? Out of all the interventions that we could put in place to positively influence pupil achievement, class size would have little impact when compared to other strategies. Who says?

Professor John Hattie, Director of the Melbourne Education Research Institute at the University of Melbourne, says that reducing class size has a “very small” effect on the quality of teaching. He considered the evidence from 113 studies in developed nations over the last 25 years and found reducing class size does enhance student achievement but only by a marginal amount. Hattie says,

The choice is not either about large or small classes or whether it is an academy or not. Instead, parents should be comparing class size with teachers’ expertise.

Some teachers can ‘manage’ large classes but they might not teach them effectively. Some can’t manage a large class or teach them well. If you are an effective teacher then size does not matter. If you have 30, 40 or 50 children in your class, if you have the expertise and skills then numbers don’t count. In fact, as reported last year by Schools Week, Sir Andrew Carter OBE, Head of South Farnham School in Surrey, planned to pilot super-size classes of 60 pupils with a single experienced teacher and why not?

The idea that large class sizes equate to an economy class experience might be true with an economy class teacher but not if the teacher is first-class. If a teacher is up to the job and can fly the plane, it doesn’t matter whether the cabin is full or half-empty.

The class size myth is something Malcolm Gladwell writes about in his book David and Goliath. He notes that a large class is normally seen to be a disadvantage for pupils, and smaller class sizes are assumed to be better. He found that smaller classes don’t necessarily lead to better outcomes because teachers don’t usually adjust their teaching style to smaller class sizes but they just work less.

Still not convinced? Many argue that small classes do make a difference and one leading proponent of this view is Class Size Matters who provide examples of research that say “reducing class size is one of the few educational strategies shown to increase learning for all students, yielding a host of cognitive and non-cognitive benefits.”

To Think About

The Education Endowment Foundation encourages to think carefully about 5 key points when considering reducing class size:

  1. Small reductions in class size (for example, from 30 to 25 pupils) are unlikely to be cost-effective relative to other strategies.
  2. Reducing class sizes for younger children may provide longer term benefits.
  3. Smaller classes only impact upon learning if the reduced numbers allow teachers to teach differently.
  4. The gains from smaller class sizes are likely to come from the increased flexibility for organising learners and the quality and quantity of feedback the pupils receive.
  5. As an alternative to reducing class sizes, have you considered changing the way you deploy staff (both teachers and teaching assistants) so that teachers can work more intensively with smaller groups (see small group tuition)?

The option to reduce class sizes is a remote one for many schools though as underfunding has forced many school leaders to up class numbers. But if the teacher quality is there, does this matter?

All political parties conveniently ignore some of the evidence about class sizes because they know it will rattle the electorate and appeal to parents who are concerned about their children being in a large class. The class size issue is a vote winner so it is best to keep parents in the dark.

Time for a reboot not a boot about.

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