Cognitive Load Theory: the Redundancy Effect

Cognitive Load Theory received a renewed level of interest last year when Dylan William tweeted that he thinks it is “the single most important thing for teachers to know”.

Since then, teachers and senior leaders have been reading on Cognitive Load Theory and trying to work out how best to apply it to their practice. We had a look at the research to see how Cognitive Load Theory can improve teaching, so that it will in turn improve student learning. In this blog, we look at four practical classroom strategies based on a subset of the theory, known as The Redundancy Effect.

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Cognitive Load Theory and The Redundancy Effect Quickly Explained

Cognitive Load Theory highlights the fact that our working memory, which is where we initially hold new information, is unfortunately pretty small. For learning to take place, this information has to be transferred to long-term memory, which is really large. That sounds simple enough; however, there is a bottleneck between the two, meaning that information that doesn’t get transferred across is ultimately lost and forgotten. Cognitive Load Theory is all about acknowledging this bottleneck and using this to improve the transfer of material between working memory and long-term memory.


Cognitive Load Theory CPD workshop for teachers


So, what is the Redundancy Effect? It is part of Cognitive Load Theory and states that giving students irrelevant information whilst they are learning something will clog up their working memory. This means students may remember the wrong stuff, not the parts of the information you actually want them to.


Using the Redundancy Effect to Improve Teaching

Fortunately, being aware of this effect allows us to devise strategies to go around it. Here are four ways that teachers can use their knowledge of the Redundancy Effect to improve their students’ learning:

  1. Reduce the Number of Words on Your Slides
    If your slides have too many words, then you can’t be sure which ones your students will remember. At worst, they will remember the wrong ones - and at best, they will be less likely to remember to right ones. Being concise forces one to prioritise, meaning only the most important bits will be highlighted.
  2. Don’t Talk Over Your Slides
    If you have key information on your slides, give students plenty of time to read it. If you are talking about something else whilst they are trying to process the content of the slide, then it is very unlikely that they will fully take in both what you are saying and what they are reading.
  3. Limit PowerPoint Animations
    It is almost frightening to think how many hours are spent adding sound to PowerPoints. These, done with the aim of making the lesson more fun or more engaging, often include adding background music and sounds. But does adding “bells and whistles” actually improve learning?
    Researchers have found that students who had no background music or sounds were able to recall a staggering 76% more than those who had neither. Chances are the students remembered the animations more than the content, which blocked up their working memory. If you want to find out more, we wrote an entire blog about how to avoid cognitive overload in your PowerPoints.
  4. Don’t Revise to Music
    Okay, so this one is more aimed at students, but it’s important for teachers to know. Researchers have found that students who revise whilst listening to music (especially if that music has lyrics) remember a lot less than those who revise in silence. This is because the music with lyrics competes for attention with the material students are trying to study, meaning redundant information works its way into their brains, instead of the subject material they are studying.

Final Thoughts

As more and more teachers explore using Cognitive Load Theory in the classroom, there are likely to be more innovative strategies developed to help aid student learning. The Redundancy Effect, which is just one arm of Cognitive Load Theory, seems to be a particularly ripe area for this. Not using excessive amount of words on slides, limiting PowerPoint animations, not talking over slides and encouraging students to not listen to music (with lyrics) whilst they learn should lead to positive outcomes and hopefully, more long-term learning.


Cognitive Load Theory CPD workshop for teachers

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