A few years ago, some teachers began advocating the application of findings from cognitive science to education. There seemed to be something not quite right about what they were advocating but I couldn’t put my finger on exactly what it was. Their focus was on the limitations of working memory and differences between experts and novices. Nothing wrong with that per se, but working memory and expertise aren’t isolated matters.
Cognitive science is now a vast field; encompassing sensory processing, perception, cognition, memory, learning, and aspects of neuroscience. A decent textbook would provide an overview, but decent textbooks didn’t appear to have been consulted much. Key researchers (e.g. Baddeley & Hitch, Alloway, Gathercole), fields of research (e.g. limitations of long-term memory, neurology), and long-standing contentious issues (e.g. nature vs nurture) rarely got a mention even when highly relevant.
At first I assumed the significant absences were due to the size of the field to be explored, but as time went by that seemed less and less likely. There was an increasing occurrence of teacher-B’s-understanding-of-teacher-A’s-understanding-of-Daniel-Willingham’s-simplified-model-of-working-memory, with some teachers getting hold of the wrong end of some of the sticks. I couldn’t understand why, given the emphasis on expertise, teachers didn’t seem to be looking further.
The penny dropped last week when I read an interview with John Sweller, the originator of Cognitive Load Theory (CLT), by Ollie Lovell, a maths teacher in Melbourne. Ollie has helpfully divided the interview into topics in a transcript on his website. The interview clarifies several aspects of cognitive load theory. In this post, I comment on some points that came up in the interview, and explain the dropped penny.
1. worked examples
The interview begins with the 1982 experiment that led to Sweller’s discovery of the worked example effect. Ollie refers to the ‘political environment of education at the time’ being ‘heavily in favour of problem solving’. John thinks that however he’d presented the worked example effect, he’d be pessimistic about the response because ‘the entire research environment in those days was absolutely committed to problem solving’.
The implication that the education system had rejected worked examples was puzzling. During my education (1960s and 70s) you couldn’t move for worked examples. They permeated training courses I attended in the 80s, my children’s education in the 90s and noughties, and still pop up frequently in reviews and reports. True, they’re not always described as a ‘worked example’ but instead might be a ‘for instance’ or ‘here’s an example’ or ‘imagine…’. So where weren’t they? I’d be grateful for any pointers.
2 & 3. goal-free effect
Essentially students told to ‘find out as much as you can’ about a problem, performed better than those given specific instructions about what to find out. But only in relation to problems with a small number of possible solutions – in this case physics problems. The effect wasn’t found for problems with a large number of possible solutions. But you wouldn’t know that if you’d only read teachers criticising ‘discovery learning’.
4. biologically primary and secondary skills
What’s determined by biology or by the environment has been a hugely contentious issue in cognitive science for decades. Basically, we don’t yet know the extent to which learning is biologically or environmentally determined. But the contentiousness isn’t mentioned in the interview, is marginalised by David Geary the originator of the biologically primary and secondary concept, and John appears to simply assume Geary’s theory is correct, presumably because it’s plausible.
John says it’s ‘absurd’ to provide someone with explicit instruction about what to do with their tongue, lips or breath when learning English. Ollie points out that’s exactly what he had to do when he learned Chinese. John claims that language acquisition by immersion is biologically primary for children but not for adults. This flies in the face of everything we know about language acquisition.
Adults can and do become very fluent in languages acquired via immersion, just as children do. Explicit instruction can speed up the process and help with problematic speech sounds, but can’t make adults speak like a native. That’s because the adults have to override very robust neural pathways laid down in childhood in response to the sounds the children hear day-in, day-out (e.g. Patricia Kuhl’s ‘Cracking the speech code‘). The evidence suggests that differences between adult and child language acquisition are a frequency of exposure issue, not a type-of-skill issue. As Ollie says: “It’s funny isn’t it? How it can switch category. It’s just amazing.” Quite.
The discussion was summed up in John’s comment: “I don’t think you can turn Cognitive Load Theory into a theory of motivation which in no way suggests that you can’t use a theory of motivation and use it in conjunction with cognitive load theory.”
6. expertise reversal effect
John says: “As expertise goes up, the advantage of worked examples go down, and as expertise continues to go up, eventually the relative effectiveness of worked examples and problems reverses and the problems are more helpful than worked examples”.
7. measures of cognitive load
John: “I routinely use self-report and I use self-report because it’s sensitive”. Other measures – secondary tasks, physiological markers – are problematic.
8. collective working memory effect
John: “In problem solving, you may need information and the only place you can get it from is somebody else.” He doesn’t think you can teach somebody to act collaboratively because he thinks social interaction is biologically primary knowledge. See 4 above.
9. The final section of the interview highlighted, for me, two features that emerge from much of the discourse about applying cognitive science to education:
- The importance of the biological mechanisms and the weaknesses of analogy.
- The frame of reference used in the discourse.
In the final part of the interview John asks an important question: Is the capacity of working memory fixed? He says: “If you’ve been using your working memory, especially in a particular area, heavily for a while, after a while, and you would have experienced this yourself, your working memory keeps getting narrower and narrower and narrower and after a while it just about disappears.”
An explanation for the apparent ‘narrowing’ of working memory is habituation, where the response of neurons to a particular stimulus diminishes if the stimulus is repeated. The best account I’ve read of the biological mechanisms in working memory is in a 2004 paper by Wagner, Bunge & Badre. If I’ve understood their findings correctly, signals representing sensory information coming into the prefrontal area of the brain are maintained for a few seconds until they degrade or are overridden by further incoming information. This is exactly what was predicted by Baddeley & Hitch’s phonological loop and visual-spatial sketchpad. (Wagner, Bunge and Badre’s findings also indicate there might be more components to working memory than Baddley & Hitch’s model suggests.)
John was using a figure of speech, but I fear it will only be a matter of time before teachers start referring to the ‘narrowing’ of working memory. This illustrates why it’s important to be aware of the biological mechanisms that underpin cognitive functions. Working memory is determined by the behaviour of neurons, not by the behaviour of analogous computer components.
frame of reference
John and Ollie were talking about cognitive load theory in education, so that’s what the interview focussed on, obviously. But every focus has a context, and John and Ollie’s frame of reference seemed rather narrow. Ollie opens by talking about ‘the political environment of education at the time ’ being ‘heavily in favour of problem solving’. I don’t think he actually means the ‘political environment of education at the time’ as such. Similarly John comments ‘the entire research environment in those days was absolutely committed to problem solving’. I don’t think he means ‘the entire research environment’ as such either.
John also observes: “It’s only been very recently that people started taking notice of Cognitive Load Theory. For decades I put papers out there and it was like putting them into outer-space, you know, they disappeared into the ether!” I first heard about Cognitive Load Theory in the late 80s, soon after Sweller first proposed it, via a colleague working in artificial intelligence. I had no idea, until recently, that Sweller was an educational psychologist. People have been taking notice of CLT, but maybe not in education.
Then there’s the biologically primary/secondary model. It’s ironic how little it refers to biology. We know a fair amount about the biological mechanisms involved in learning, and I’ve not yet seen any evidence suggesting two distinct mechanisms. The model appears to be based on the surface features of how people appear to learn, not on the deep structure of how learning happens.
Lastly, the example of language acquisition. The differences between adults and children learning languages can be explained by frequency of exposure and how neurons work; there’s no need to introduce a speculative evolutionary model.
Not only is cognitive load theory the focus of the interview, it also appears to be its frame of reference; political issues and knowledge domains other than education don’t get much of a look in.
the penny that dropped
Ever since I first heard about teachers applying cognitive science to education, I’ve been puzzled by their focus on the limitations of working memory and the characteristics of experts and novices. It suddenly dawned on me, reading Ollie’s interview with John, that what the teachers are actually applying isn’t so much cognitive science, as cognitive load theory. CLT, the limitations of working memory and the characteristics of experts and novices are important, but constitute only a small area of cognitive science. But you wouldn’t know that from this interview or most of the teachers advocating the application of cognitive science. There’s a real risk, if CLT isn’t set in context, of teachers getting hold of the wrong stick entirely.
Geary, D. (2007). Educating the evolved mind: Conceptual foundations for an evolutionary educational psychology, in Educating the evolved mind: Conceptual foundations for an evolutionary educational psychology, JS Carlson & JR Levin (Eds). Information Age Publishing.
Kuhl, P. (2004). Early language acquisition: Cracking the speech code. Nature Reviews Neuroscience 5, 831-843.
Wagner, A.D., Bunge, S.A. & Badre, D. (2004). Cognitive control, semantic memory and priming: Contributions from prefrontal cortex. In M. S. Gazzaniga (Ed.) The Cognitive Neurosciences (3rd edn.). Cambridge, MA: MIT Press.