The single most important thing for teachers to know…

WIliam CLT

Dear Reader,

There is a lot being written about Cognitive Load Theory (CLT) and how important it is. I have written this blog to share my understanding – please send me corrections, recommendations and advice.

My own understanding has been developed through:

  • Hattie’s ‘The Science of How We Learn”
  • Willingham’s “Why Students Hate School”
  • Kellog’s “The Psychology of Writing”
  • Oliver Caviglioli’s summary of Sweller’s “Cognitive Load Theory”

My aim it to add something useful for teachers. I am a teacher, not a psychologist. Please send me corrections and recommendations so that I can improve this post.

Thank you for taking the time to read it. I hope it is useful.


Cognitive Load Theory, and How to Use It

Here is my explanation for how cognitive load theory works and how to use it.

CLT schematic (2)
A Model Of Cognitive Load Theory

First comes the model of the mind.

In my simplified version of the model, there are three elements: short term memory, long term memory and external memory.

Long-Term Memory

Our long term memory stores knowledge and schemata – knowledge organised in useful ways. Schemata include:

  • social knowledge – people, interactions, relationships.
  • subject knowledge – e.g. knowledge about astronomy or the Tudors or rivers.
  • reading knowledge – how to decode, vocabulary, knowledge about layout, diagrams etc.

Our aim as teachers is to develop our students’ long-term memories. This what makes students more knowledgable, better problems solvers and more creative.

Short-Term Memory

Short term memory is where we store information which we need to use to complete a task, but which is not stored in our long-term memories. The information might include:

  • data to solve the task.
  • information about the task.
  • relevant processes.
  • novel social interactions/relationships.

The important thing for teachers to remember is that the short-term memory is easily overloaded – three things to remember is usually too much. If you are asking students to carry out a novel task collaborating with new people using data they haven’t memorised, and hope that they will be able to reflect on their learning at the same time, you may be out of short-term memory, and out of luck.

External Memory

When the task gets tricky, short-term memory gets strained. That’s why we resort to counting on finders, scribbling on the backs of envelopes, and working with someone else. Making use of external memory is a powerful strategy to relieve some of the pressure on short term-memory. Teachers should show students how to make use of it.

Using CLT in Lessons

When our students learn, they are developing the schemata in their long-term memories. Our main job as teachers is to boost students’ schemata. This means thinking hard about what we want our students to be able to recal instantly and with little effort.

The key strategy suggested by CLT is reducing the amount of extraneous information held in short-term memory. The tasks you set should be challenging, but you overload short-term memory, the student will learn little.

CLT schematic learning
Suggestions for Improving Learning using CLT

I have written about several methods for improving learning using Cognitive Load Theory in previous blogs:

Using worked-examples and completion-problems to reduce cognitive load.

Reducing cognitive load by going goal-free and using cooperative learning.

Reducing the split-attention effect.

I think cooperative learning strategies are going to play an increasing role n the classroom as we develop our teaching in the light of CLT. I am currently working with Jakob Werdelin on develping cooperative reading strategies and will write more on this soon.





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