It was Dylan Wiliam who tweeted on 26 January 2017 that he had ‘come to the conclusion that Sweller’s Cognitive Load Theory is the single most important thing for teachers to know’. Given that teaching and learning is a very wide-ranging and complex domain, that’s a huge statement for him to make. I agree: I think that teaching that ignores cognitive load theory is bad teaching.
What is ‘cognitive load’?
‘Cognitive load’ is the term used to describe the capacity of our working memory. We can think about our working memory as our consciousness – it’s the place in our brain where we think. So when we are thinking about something – What shall I have for dinner this evening? – it’s our working memory (also called our short term memory) that we are using to do it.
The problem with our working memory
The problem is that we can hold very little information in our working memory at any one time. To illustrate this point, try right now to BOTH think about what you will have for dinner this evening and the lyrics of a favourite song; you will not be able to do it – you just can’t do both of those things at the same time. If you try to do it, you may have a sense of being at least partially successful, but if that’s the case, what you were actually doing was switching rapidly between the two different tasks: ‘For dinner tonight I’ll make some pasta’ … ‘And bye bye Miss American Pie, drove my chevy to the levy…’ ‘With my pasta, I’ll have some passata and bacon’ … ‘And the levy was dry, those good old boys were drinking whisky and rye…’ … ‘and maybe a few mushrooms’. That’s rapid switching between thinking about the two things; it isn’t thinking about both things simultaneously.
John Sweller, grandly dubbed ‘the godfather of cognitive load theory’ by the TES in 2017, has spoken and written at length about the extraordinary limitations of working memory and how educators should respond to those limitations. If we accept that ‘learning’ is essentially about accumulating information in our long-term memory, then as educators we must confront the significant challenge of getting a load of ‘non-instinctive information’ (the stuff people have to learn at school) past our students’ very limited working memories and into their long term memories. So how best to do it?
Techniques for overcoming the limits of our working memory’s capacity
Here are some of the key techniques Sweller and others recommend for getting information past the bottleneck of our working memory.
- Presenting new information explicitly and clearly – absolutely not through problem-solving activities or ‘discovery learning’, as those activities can quickly overwhelm our working memory: ‘Just tell ‘em!’ (Olivia Dyer, The Michaela School)
- Presenting new information in small chunks at a time, plus: checking for understanding; providing opportunities for both guided and independent practice; providing feedback and helping students fill in their knowledge gaps
- Regularly reviewing with students what they have learned from the chunked teaching, particularly by asking good questions as these will make clear what has been learned – and crucially, what hasn’t – and then filling in the learning gaps
- Scaffolding learning, and using other forms of support such as prompts and cues – particularly for learners with less prior knowledge; the rule of thumb here is the less we know about a thing, the more we benefit from the support that is provided through activities such as scaffolding
- Using worked examples and partially-worked examples – these really help avoid overloading working memory capacity. Scaffolding can be faded out as the students’ knowledge grows through practice
- Students working collaboratively – but this has to be carefully managed by teachers or else some students may opt out out, do little work etc…
- Dual coding – provided the use of more than one mode of input is not redundant – the presentation of redundant material will inhibit learning
Things for teachers to be VERY wary of
For novice learners – a category to which almost everyone who goes to school belongs – we need to avoid, like the plague:
- Discovery learning
- Using problem solving activities or enquiry learning to teach new information (solving problems is fine once there is sufficient background knowledge in students’ heads to enable them to cope)
- Presenting too much information at one time
- Confusing students through multi-modal input (by which I mean, for example, putting up a slide full of text on the digital screen while talking at the same using different language from the language on the screen – what are they meant to be paying attention to?)
- The wrong level of challenge in the material (too easy or too hard) – obviously.
When presenting new information, learning will be hugely hampered if we ignore the severe limitations of students’ working memory; but if we use techniques that support working memory – such as worked examples – we will have far greater success in helping students learn.
