Why schools should decide on class sizes

I have a column in today's Independent making the case for headteachers to be free to decide on class sizes in their own schools, contrary to teaching union demands for legal limits. You can read the piece here, but these paragraphs sum up my argument:

The NUT might be on stronger ground were they calling for smaller infant class sizes, though ....studies....suggest that further real benefits for this age group require classes of below 15. But the biggest problem with the NUT ultimatum is that it wants the Government, rather than head teachers, to micro-manage schools. It was, after all, schools and their leaders who decided to use the extra money they got from government to employ more support staff.

And it is schools that occasionally opt to use classes of 70 to teach in different ways. Contrary to the more excitable headlines, such classes are usually well-run and are used to enrich students' learning experiences rather than to save money. One such class that I saw in an excellent West Midlands school used a large classroom with computers to set a range of challenges to a mixed age-group; it stretched able students and it allowed very personalised learning, regulated by a teacher supported by a host of teaching assistants. There was no evidence that pupils – or teachers – were losing out; in fact, quite the contrary.

Of course, such classes are not for all – or even most – situations. But they can play a part in a rich teaching and learning programme, just as masterclasses or lectures from university dons may mix several classes together. And the possibilities of broadband technology allow distance learning to widen A-level choices across groups of more than 20 students.

The point is not that these should become standard practice, but that they should not be outlawed in favour of a measure for which there is little beneficial evidence. What matters most is to enable every student to maximise their potential. And for that to happen, head teachers should have the freedom to try approaches that work best for their schools.