Cognitive load theory – some strategies to teach light

In the last few years, cognitive load theory (CLT) has been receiving a lot of attention by educators and has started to shape the classroom practice of many teachers. So, what is CLT? Alessio Bernardelli, a member of the IOP’s Professional Practice Group, explains.

The simplest way to think about it is that cognitive load is the heavy lifting the brain has to do when completing tasks. If you can reduce the cognitive load of the task, the learner can focus on the relevant information.

The value of cognitive load theory is that it helps us sequence and design activities which are well suited to learning more and learning to solve problems. Reducing the cognitive load of a task means students can focus on the important concepts and learn more efficiently.

It is inefficient to continue with new learning unless this knowledge is secure. This can take several lessons. So before moving on to the next stage of the learning, this knowledge needs to be well embedded. Quizzing is a very effective way to do this, as is comparing similarities and differences.

Working memory

Your working memory is your thinking workspace. It can only really cope with two or three new things, but it can draw on previously learnt things really easily. So the key to efficient learning is to build a well-stocked long term memory. You need to do this one small piece at a time.

An example to reduce the cognitive load when reading about refraction

The diagram above is adapted from a paragraph in a textbook and should reduce the cognitive load. The labels make it simple for the reader to match the text to the relevant part of the diagram. Previously, the reader had to hold that information in the working memory. The diagram is also easy to search for information, compared to the text. If you want to go back and check one part of the argument, it is much easier to find than in a paragraph.

Graphic organisers

Graphic organisers are particularly useful, both as a teaching method and as a retrieval task for students to develop their own. This is an example of a graphic organiser incorporating different elements of light. 

Ben Rogers, author of The Big Ideas in Physics and How to Teach Them contributed to this article.


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