Over the Australian Summer I finally decided to read John Hattie’s Visible Learning for Teachers.

Hattie’s theories on education are backed up by countless research papers and evidence.

In the never-ending quest to improve teaching (and teachers) Hattie is as revered by politicians and system leaders around the world as he is viewed with suspicion by front-line teachers.

His most controversial assertion is that reducing class size is a waste of time and money. His research proves having fewer kids in class has little impact on teaching and learning.

And don’t the politicians love that!

Bigger Classes = Fewer Teachers = Less money needed for education – Take that Gonski!

In Queensland, the state government has moved to remove the maximum class size limit, presumably confident of a Coalition victory in the September Federal Election, given that Shadow Education Spokesman Christopher Pyne is on record as saying that class sizes have little impact on teaching.

But here’s the thing… each of the interventions that Hattie studied, were done so in isolation.

Does reducing class size in and of itself improve teaching? Is it the silver bullet? 

Of course not. A crap lesson in front of 40 kids will still be a crap lesson in front of 20. Hattie himself makes the point that looking at class sizes in isolation showed that some teachers didn’t change their methods regardless of the number of kids in front of them.

But when you look at Hattie’s list of interventions that he claims DO have a great impact then things really start to get interesting with regard to class size.

A teacher’s ability to implement any one or all of these interventions is impacted on by the amount of kids they have in front of them. Anyone who says different has no understanding of teaching, or is clinging to this ideology because it’s the theory du jour and is probably helping them climb the international speaking ladder.

So when politicians say that they won’t be supporting a reduction in class size, what they are actually saying is that they do not support the concepts of developing high expectations for each student, providing quality feedback, improving teacher-student relationships, implementing quality vocabulary or comprehension programs. What politicians are saying is “We’re not particularly interested in improving teaching and learning in our schools. It’s just a little bit too expensive.”

This myth of class-size being irrelevant has permeated into the education debate in many countries like the UK and US. Although, interestingly not Finland where the government agreed to reduce class size, and now the average class size is around 20 kids, with science lessons capped at 16. Sixteen!!

I’m not dismissing Hattie’s work out of hand as I agree with every single one of his “High Influence” interventions for improving teaching & learning – it’s just that having smaller class sizes is essential in order to enable teachers to implement these interventions.

You can read more about the mathematics behind effect size here…