The title of my speech was ‘Statistical significance and theoretical frameworks: how can we discover the root causes of successful teaching and learning?’, which is a bit of a mouthful, I know. Here’s a (relatively) quick summary.
The first half of my speech leant very heavily on this ED Hirsch article. I really recommend you read it – it is superb. Briefly, Hirsch shows some of the problems with one of the most-tested issues in education – class sizes. He shows that a very methodologically robust study in Tennessee demonstrated that smaller class sizes did help pupils learn. Policymakers in California therefore spent $5 billion on reducing class sizes. But the expected gains did not materialise. Instead, in the words of a Scientific American article on this issue, this policy ‘consumed billions of dollars, produced only minuscule gains and even some losses.’
Hirsch then goes on to argue that we don’t just need trials that show whether certain interventions are or are not statistically significant. We need to know what causes the statistical significance. We need to know why. He argues that theory – in this case, cognitive science – can provide us with the reasons why certain interventions are or are not successful, and which interventions are or are not likely to be successful. Theory can help guide us as to the right questions to ask in our RCTs. Hirsch makes an analogy with medicine in this article.
‘Medical science continues to advance as it becomes allied with ever more refined laboratory understandings. Its most striking and reliable advances have occurred since medicine became closely tied to biochemistry at a still more fine-grained level — the molecular. By analogy, it is plausible to think that progress in educational research, if it occurs at all, will follow this sort of pattern.’
I also quoted this lovely line from Steven Weinberg, which I actually first read in Hirsch’s book The Knowledge Deficit.
‘Medical research deals with problems that are so urgent and difficult that proposals of new cures often must be based on medical statistics without understanding how the cure works, but even if a new cure were suggested by experience with many patients, it would probably be met with scepticism if one could not see how it could possibly be explained reductively, in terms of sciences like biochemistry and cell biology. Suppose that a medical journal carried two articles reporting two different cures for scrofula: one by ingestion of chicken soup and the other by a king’s touch. Even if the statistical evidence presented for these two cures had equal weight, I think the medical community (and everyone else) would have very different reactions to the two articles. Regarding chicken soup, I think that most people would keep an open mind, reserving judgment until the cure could be confirmed by independent tests. Chicken soup is a complicated mixture of good things, and who knows what effect its contents might have on the mycobacteria that cause scrofula? On the other hand, whatever statistical evidence were offered to show that a king’s touch helps to cure scrofula, readers would tend to be very sceptical because they would see no way that such a cure could ever be explained reductively…How could it matter to a mycobacterium whether the person touching its host was properly crowned and anointed or the eldest son of the previous monarch?’
Continuing the medical theme, I quoted John Snow in my speech. In one of his appearances at a Parliamentary investigation into cholera, Snow was asked ‘Is your opinion derived from practical experience, or is it mere theory of your own?’ Snow’s reponse was masterly: ‘My theory is derived from practice, and from observation.’
Sometimes, as with Snow’s interviewer, we treat the word theory with scepticism. We see theory as being opposed to hard-headed and realistic practice. But in fact, as Snow’s response shows, theory and practice should go hand in hand. And the alternative to theory isn’t pragmatism. The alternative is the wrong theory. As Keynes argued, in one of my all-time favourite quotations, ‘Practical men, who believe themselves to be quite exempt from any intellectual influence, are usually the slaves of some defunct economist.’
And as Dan Willingham said earlier that morning, ‘every teacher inevitably has a theory about how pupils learn.’
In the second half of my speech, I tried to show three ways in which being dependent on the wrong theory had affected my classroom practice. That is, I showed three particular ways in which I hadn’t been consciously aware that I had been depending on theory – I thought I’d just been depending on ‘common sense’, or that I was ‘being pragmatic’. But in fact, I had been depending on a particular theory about how pupils learn, and that theory had turned out to be flawed. I then showed how knowledge of a particular research paper could have helped me avoid these mistakes. Here are the examples of my practice together with the research paper that addressed this theory.
Practice – Teaching pupils with limited vocab how to use a thesaurus.
Research paper – Miller G.A. and Gildea P.M. How children learn words. Scientific American 1987; 257: 94–99.
Practice – Teaching pupils reading strategies.
Research paper – Recht D.R. and Leslie L. Effect of prior knowledge on good and poor readers’ memory of text. Journal of Educational Psychology, 1988; 80: 16–20.
Practice – Teaching grammar through a project.
Research paper – Nickerson , R. S. Adams , M. J. (1979). Long-term memory for a common object. Cognitive Psychology, 11, 287-307
In summary, we need to work out why stuff happens! Not only will this need to better teaching and learning, it is also lots of fun.