Two tweets on my timeline today have been the stimulus for this blog. That’s what I like about edu-twitter and why I think it’s fantastic CPD for new and experienced teachers alike. You are drawn into the most current conversations about education and these take your thinking into new directions or cement an idea already forming in your mind.
In today’s case, the two tweets were as follows, on the same issue but taking different slants. The first one was by Daryn Egan-Simon:
The second tweet that set me thinking and writing this blog was posted by Sam Strickland, the organiser of today’s ResearchEd Northampton conference, which I was sadly unable to attend. Sam shared an interesting quote from Tarjinder Gill‘s talk:
As most of you will be aware, a key part of Cognitive Load Theory is the idea that working memory is limited and can get easily overloaded. We can only retain a few bits of information in our working memory at a time, so to engage in complex thinking, we have to make use of information stored in our long-term memory, which is unlimited. To aid our pupils by-pass the constraints of working memory and to solve complex problems or write sophisticated analysis, we should focus on purposefully building schemas of information in their long-term memories that they can retrieve when needed.
Cognitive Load Theory became the latest big thing after the edu-guru, Dylan Wiliam, posted this tweet about it over two years ago.
Now as it happens, I disagree with William on this. I don’t believe Cognitive Load Theory is the most important thing for teachers to know, but I do think it is vital for curriculum leaders to know it and act on it. For to me, the greatest implication of CLT is for how we sequence curriculum to help our pupils build the knowledge base that will allow them to do all sorts of sophisticated thinking and tasks further down the line. That’s not to say it has no value for active teachers in the classroom, of course it has, but I would not rank it of the highest importance.
Tarjinder Gill’s description of working memory as a bottle neck brought back a memory of something I learned about a quarter of a century ago (yes that long) from when I was studying for my MBA. I was given a book called The Goal by Eliyahu Goldratt, which puts forward the Theory of Constraints, a management theory which focuses on finding and addressing the constraints that are creating bottle necks in the throughput of a business. I was immediately struck by the parallels between the Theory of Constraints and Cognitive Load Theory. Whilst one was formulated for business and the other for education, they both have in common this idea of bottle necks or constraints which impede either the learning or the productivity.
And I was reminded of the example that Goldratt uses in his book to illustrate the Theory of Constraints. The protagonist of the book is a character called Alex, a plant manager whose factory is struggling to manufacture and ship orders to customers on time. Alex meets an old friend called Jonah (a fictional version of Goldratt) who gets him thinking about the choke points that are constraining the factory’s output and to see that the whole factory can only move as fast as its slowest element. Later in the book, Alex gets an opportunity to put the Theory of Constraints to the test, not in his factory but on a hiking trail with his son’s scout group.
Alex notices that the single file line of scouts never manages to maintain a consistent pace, but is constantly stopping and starting. The speedy children at the front are zooming ahead, but having to stop to let Herbie, the chubby boy, catch up with them. In this context, Herbie is the choke point or bottle neck, slowing down the whole group (this book was written decades ago before we got all politically correct, so please don’t get uppity with me for talking about a chubby boy slowing everyone else down). The group can only move as fast as its slowest element – Herbie – and so it makes sense to bring Herbie to the front of the line and to lead the pace. This way, there is no constant stopping and starting. The contents of Herbie’s backpack are distributed to the other children, lightening Herbie’s load and thus helping him to walk faster.
So when Tarjinder Gill spoke of working memory as a bottle neck, I was transported back to the example I describe above. What a great way to put it! Working memory is a bottle neck. Like Herbie on the scouts trail, our pupils can only think as fast as their working memory will allow them. Overload that working memory with too many new concepts, and it will create a bottle neck. And as Herbie was helped to go faster by having the group walk behind him and the contents of his heavy backpack shared amongst them, we need to help our pupils avoid the bottle necks in their working memory by consistently building up, over time, a repository of information – the schemas – that they will need to process complex ideas and develop sophisticated thinking.
Is Cognitive Load Theory a fad, as suggested by Daryn Egan-Simon in the first tweet I shared? I believe not. It has very important implications for how we design curricula. Having CLT at the forefront of their minds will help curriculum leaders ensure that important concepts, skills and vocabulary that pupils will require are embedded and stored in long-term memory during their curricular journey in the school. This is a painstaking and time consuming process, but done well, should reap great rewards further down the line.
That’s not to say there aren’t many edu-fads still out there. I’ve only been working 4 years in the British education system, and already I have seen some big ideas come and go – witness the current near demise of Growth Mindset. I wouldn’t be surprised if someone who has been teaching several years were to develop some healthy cynicism about the latest edu-theory. In this case, however, I think the cynicism is misplaced.