Cognitive load theory has fundamentally changed my teaching. You can neatly separate how I taught before and after reading the work of Professor John Sweller, and I have no doubt that the “after” me is the better educator.

Cognitive load theory (CLT) is based on the idea that our working memory can deal with only a limited amount of information at one time. Sweller refers to it as the “load” on working memory being too high, too low or just right. The theory identifies three different types of cognitive load:

• Intrinsic cognitive load - the inherent difficulty of the material (which can be influenced by prior knowledge of the topic).
• Extraneous cognitive load - the load generated by how the material is presented (which does not aid learning).
• Germane cognitive load - the elements that aid information processing and contribute to the development of schemas.

It should be noted that Sweller has actually removed “germane load” as an independent source of cognitive load, but it occurs elsewhere (Sweller, 2010).

In short, Sweller’s work highlights the problems with overloading our working memory and the impact this has on the completion of tasks and, more importantly, the transfer of information from our short-term, finite working memory to our (theoretically) infinite long-term memory.

How brains work

In what way has this changed my approach? CLT has given me a firm understanding of how brains work in layman’s terms. Sweller’s papers explain learning from a psychological point of view in a way that I, as a normal classroom practitioner, can understand.

The advantage of this is that I can make decisions when planning to ensure that learners aren’t overloaded with unnecessary inputs and stimuli. Now, every task I set, everything I say and every question I ask is in some way linked to the concepts put forth by Sweller. Most of the approaches I adopt are directly derived from the findings; if not, they are influenced or inspired by elements of CLT.

For example, I know intrinsic cognitive load can be reduced by breaking down subject content, sequencing the delivery into small chunks so pieces are taught individually before being explained together as a whole. CLT makes sense of this kind of approach. For me, it answers the question I’m always asking: “Why does that help learning?”

Meanwhile, I have come to believe that excessive extraneous load was the cause of at least 90 per cent of the issues I faced when I first started teaching. I made cards and did whizzy things with PowerPoint. I was mixing up the content with lots of other irrelevant elements and my students were overloaded.

In short, Sweller made me realise that one of the highest-impact factors on new learning is actually a lack of clarity in instruction. A good example might be a lesson that uses a PowerPoint featuring a lot of text and the teacher talking at the same time. It seems obvious now that this might overload some students. But I look back at when I started teaching and my initial reaction to blank looks was to explain a concept again with different words. Sweller taught me to strip back my teaching to the essentials.

Avoiding potential issues

There are, of course, potential issues with CLT. Reif (2010) writes that if cognitive load is reduced too much, learning essentially becomes fragmented. Holton (2009) points out that it is difficult to measure cognitive load and, therefore, difficult to generate evidence to prove the theory. And in Tes, Alistair McConville questioned how useful the theory was beyond basic indicators of best practice.

But for me, it works. The key aspects I took away and now apply in every lesson are to:

• Break down subject content when introducing new topics and make time to recap and recall information.
• Present instructions clearly without introducing too much information at the same time.
• Be wary of reducing cognitive load too much - you don’t want the desirable difficulty to be too low.

Admittedly, measuring the outcomes of this shift is incredibly difficult - who knows what variables are at play in improved results? But there is a pace in my lessons now that may have been lacking before. There are fewer incidents of incomplete recall and I don’t have battles with students failing to follow instructions.

Another issue I have reduced, if not abolished, is task abandonment - now that I understand how to keep extraneous load low, learners are significantly more engaged with the tasks that I set.

Essentially, my classroom is a better place for me and my students because of cognitive load theory.

Adam Riches is a senior leader for teaching and learning, head of English and specialist leader in education

This is the third in a four-part series. Next week: behaviour management

This article originally appeared in the 23 August 2019 issue under the headline “Lighten the cognitive load”