Tonight’s 15 minute forum was led by Andy Tharby. Andy’s session was based around his own blog on the same topic, but also this one by Nick Rose. The premise of his session was very simple. As teachers, we put a huge amount of effort into thinking about, planning and then delivering our lessons – but is all the stuff that we do as effective as it could be? The evidence would suggest not. We work long hours, but compared to other countries, the performance of our students is not great. So this raises an important question:
How can a basic understanding of cognitive load theory help us to become more effective teachers?
Much of our understanding about cognitive load theory, comes from the work of John Sweller. He was interested in how teachers might manage the ‘load’ they put on the working memory of our students.
When thinking about memory, we should think about it in terms of working memory and long term memory, as shown in Daniel Willingham’s diagram above.
- Working memory – this is where new information from the environment is processed. We think that most people can only process between 5-9 items at any one time – and that this is limited in individuals i.e. it can’t be changed. It’s easy to see how this is problematic for students e.g. in maths, if students are having to remember multiple steps in order to solve a problem, they may well ‘overload’ their working memory.
- Long term memory – where huge (unlimited?) amounts of information can be held indefinitely – a bi like the hard drive of a computer. Although we have a huge capacity for memory, the problem is getting it to stick…and then being able to retrieve it.
Lots of information from the environment will not be processed by the working memory – it will be missed. As teachers, what we want to do is to maximise what gets transferred from the working memory, into the long term memory. Once something is stored as long term memory (a schema), it can then be easily retrieved and used. This then frees up the working memory to process other information. A good example of this multiplication tables. If students are able to commit multiplication tables to their long term memory, they can solve mathematical problems more efficiently. Why? They don’t have to use their working memory on the multiplication tables, so can use this on other aspects of the problem solving process.
Cognitive load refers to the total amount of mental effort being used in the working memory. Sweller argued that teachers can adapt their teaching to reduce cognitive load in learners. Cognitive load theory differentiates cognitive load into three types – intrinsic, extraneous and germane:
- Intrinsic load – this is the inherent difficulty of the material being learnt e.g. spelling ‘cap’ is easier than spelling ‘catastrophe’. There is nothing we can do with that.
- Extraneous load – this is any difficulty created by how the task is presented e.g. some problems may be presented to students with very limited input from the teacher – so putting an extra, unhelpful load on the working memory. An example is switching – so when we have to move our attention from one place to another. This also places an unhelpful on our working memory. An example of this is labelled diagrams – we have to witch our attention from the label to the diagram. This is not helpful. Evidence suggests that we can make this easier by placing the labels on the diagram.
- Germane load – this refers to the work put into creating a permanent store of knowledge (a schema). Research suggests that a degree of thinking is required to create these new schemas – hence the importance of ‘think hard’ questions.
Thinking about germane load explains why it so important to keep students in the ‘struggle zone’. By making sure that there is the right amount of challenge, we are making students think – and when they are thinking, they are more likely to create schemas.
Implications for teachers…
- Teach fewer concepts per lesson – if we try to do too much or go too quickly we will overload the working memory. This has implications for planning too – plan to do less, but do it better.
- Teach in ‘chunks’ (the more difficult, the more chunking is needed) – as students become more proficient, we can adjust this.
- Limit distractions – if we want students to think hard, we need to limit the extraneous load. One very basic way of doing this is for students to work in silence, when they are having to think really hard. That’s not to say that students should sit in silence all lesson, every lesson – but it will certainly help when they are having to think really hard.
- Limit the number of success criteria, or procedural processes, that students work on in one go – so, when giving students instructions or information, remember that, on average, their working memory will struggle to process more than seven items.
- Use models and worked examples – if students have to ‘memorise’ methods of solving problems, that are not in their long term memory, it will use up working memory. They can be helped with this, by providing them with a worked example, that they can then use to help solve the problem. So, if students are having to carry out a complicated mathematical problem, provide them with a worked example that they can look at and then use to solve another , similar problem.
- Use images to support language – research suggests that we can process images and language at the same time – it doesn’t impact the working memory. So, use visuals at the same time as you are explaining a particular idea.
- Avoid switching their attention – rather than placing labels to diagrams on the side of the diagram, place them inside the diagram.
- Plan for two or three tasks per lesson – revisit the same material, but in slightly different ways. Another tip is to use less powerpoint slides – but go into the ideas on each one, in much greater depth.