Cognitive Load Theory (CLT) is all the rage. It was cited by Ofsted in their new inspection framework, it is discussed at educational conferences and it is finding its way into CPD sessions in schools up and down the country. 

What is it?

CLT is a theoretical model that seeks to explain how learning takes place and which methods of “instructional design” (or “teaching” to you and I) will be most effective as a result. 

At its heart are two commonly accepted ideas. The first is that our working memory is extremely limited, the second is that our long-term memory is essentially limitless; we can store information and retrieve it when needed, thereby freeing up space in our working memory. 

The theory suggests that we consider the “load” placed on working memory by a task pupils have been given. This load comprises of two parts. The intrinsic load is created by the complexity of the task itself.

The more difficult the task, or the more novel the information (how far it is removed from what the pupil already knows) the higher the load. 

We want to manage the intrinsic load but not necessarily reduce it. We want our pupils to tackle difficult tasks as it makes them think hard (and, as cognitive scientist Daniel T Willingham reminds us, “memory is the residue of thought”). 

The second kind of load we want to consider is the extraneous load. These are pressures put on the working memory by things outside the material being learned.

They might come from overly complex instructions, distractions in our environment or being given too much additional information. 

We can therefore think of CLT as a way of designing how we teach to support pupils learning complex ideas by supporting them with the intrinsic load of a task whilst reducing the extraneous load. 

The single most important thing...

So, is cognitive load theory the “single most important thing for teachers to know” as suggested by emeritus professor of educational assessment at UCL, Dylan Wiliam, or is it just common sense? I’d argue it is both. 

The problem that CLT has, if it could be described as a problem at all, is that it just supports how excellent teachers have always taught. It provides the rationale for why that works and helps less experienced teachers leapfrog some of the trial and error that they might have to go through to reach this level of understanding themselves. 

It also challenges some of the ways we have been encouraged to teach in the past. For example, that pupils will learn best by discovering things for themselves. 

CLT reminds us that pupils start a topic as novices and as such much of what they are learning will be unfamiliar and the intrinsic load will be high.

They won’t have much information about the topic stored in their long-term memory to draw on (their schema) and so will benefit from material being presenting in small, simple, steps with plenty of opportunity to practice after each step until they develop a greater understanding. 

At this point they will benefit from more complex, problem-solving type tasks using what they have learned so that they have the opportunity to retrieve what they have learned and apply it to new situations. 

This theory also suggests that during the early stages of a topic we will want to support our pupils’ working memory by providing worked examples that show how an expert (you, the teacher) reaches an answer to a question before they try and complete a similar task themselves. 

It helps to reduce their need to think through the steps (holding this in their working memory) at the same time and thinking about the information they will need to use. Over time we will want to remove this scaffolding so that pupils practice all the stages themselves. 

The final foot

As with all educational research, it means very little until it has been filtered through the professional expertise of those in the classroom.

One of the most useful guides for teachers on CLT was produced by the New South Wales’ Department for Education and called Cognitive Load Theory in Practice. This guide talks through seven strategies drawn from CLT with illustrations on how they might look on the ground.

They suggest:

1. Tailoring lessons to a pupils existing knowledge and skills. Building on prior knowledge reduces how much novel information needs to be handled in the working memory.

2. Using worked examples to teach pupils new content or skills. As discussed above, these examples help pupils to think about what is being learned rather than the steps to complete a task. 

3. Gradually increase independent problem solving. Pupils need the opportunity to practice applying information to new contexts but now until they have learnt this information. 

4. Cut out inessential information. This could be extraneous information on a slide, interesting tangents in your explanation or irrelevant detail on a diagram. We need to direct pupil attention to the information they need. 

5. Present all essential information together. Pupils will struggle to hold the information presented on one slide and apply it to the information another. If the explanation you gave at the start of the lesson needs to be applied to the diagram given 10 minutes later, include the relevant information again on the diagram.

6. Present oral and visual information together. This takes advantage of dual-coding which is our ability to take in information on two channels and makes this information easier to process. 

7. Encourage students to visualise what they have learnt. This encourages pupils to draw information out of their long term memory and review what they have learnt. 

CLT only provides a model for how pupils learn and what this might mean in terms of instructional design. What any of this actually looks like in the classroom comes down to what Rebecca Boomer-Clark of the Ark academy chain calls “the final foot” - that space in the classroom between the teacher and their pupils. 

It is in this final foot that the teacher must decide how to manage the intrinsic difficulty of a task and ensure the level of challenge is pitched right.

It is in this final foot that they must work out when to model and when to allow the pupils to fly solo. Cognitive load theory may be “the most important thing for teachers to know” but only teachers will know what to do with it next. 

Mark Enser is head of geography and research lead at Heathfield Community College. His latest book Teach Like Nobody’s Watching is out now. He tweets @EnserMark