Does classroom size really matter, Mr Clegg?

Guardian Education blog. The Lib Dem leader's policy pledge to reduce early years class sizes may seem like common sense – until we realise how impracticable it is.

Nick Clegg at the Liberal Democrat conference in 2008

Lower class sizes are one of the things about Scottish education that excite envy in the English, and one of the Scottish National Party‘s most popular manifesto pledges was to cut early primary class sizes down to 18. Is the Liberal Democrat leader Nick Clegg, whose name is Scots for a large annoying fly, a student of Scottish politics?

A cynic might say he was, as his latest policy pledge of reducing early years class sizes to 15 certainly resembles the SNP’s . But although the promise played well at the last Holyrood election, it has not come to pass.

A series of legal challenges as well as lack of classroom space have shot it full of holes – but this doesn’t seem to have put off the English Liberal Democrats. But like the SNP, I suspect the Lib Dems would find this pledge impossible to implement.

A couple of years ago, I interviewed parents at a popular primary in Falkirk in central Scotland about the idea. “Oh we would love smaller classes here,” said one mum. “Until it meant we couldn’t get our kids into this school. Then world war three would break out.”

That proved to be a prophetic remark. In theory small classes sound great but children don’t live in a theoretical world. Most parents would rather see their child shoehorned into a full classroom in a “good” school than at a half-empty row of desks in the sink estate a mile away.

It is not just about money, it is about the fact that most urban schools cannot simply have extra classrooms grafted on to them.

In Scotland, several families challenged this ruling when it meant their children were denied entry to the school of their choice on the grounds that it was “full”. So far, councils have lost and been forced to give places to local children up to the maximum set in law of 30.

In other areas, schools have had to create composite classes of different year groups in order to make space for small primary one (reception) classes – something which has not gone down well with parents either.

Class sizes of 15 are very small. Even in the private sector the average class size is around 19 north of the border. And the Organisation for Economic Cooperation and Development average is 21.5.

Research from the US which proved that black, disadvantaged children in the state of Tennessee did better in small classes – the Star project – is often quoted. But that study was arguably of limited relevance to the UK as it compared classes of 17 to 24.

And although Peter Blatchford, who has done more research on this than anyone in Britain, found a small effect on attainment in the early years, he also found that there were slightly more problems between the children in the small classes and that not all teachers could make good use of smaller class sizes.

The writer Malcolm Gladwell, in a recent issue of the New Yorker, argues that the evidence appears to be stacking up that expensive adjustments to class size don’t affect attainment nearly as much as teacher quality.

One confident, motivated teacher working in a supportive environment and dealing with 25 kids probably beats any amount of fly, pie in the sky promises.