Cognitive Load Theory was developed by John Sweller. He published a paper on the subject in the journal Cognitive Science in 1988.
"Cognitive load" relates to the amount of information that working memory can hold at one time. Sweller said that, since working memory has a limited capacity, instructional methods should avoid overloading it with additional activities that don't directly contribute to learning.
For example, a labelled diagram places a lower demand on your working memory than one that has the labels listed at the side.
Dylan Wiliam has described cognitive load theory as ‘the single most important thing for teachers to know’. Cognitive load theory uses knowledge of the human brain to design teaching strategies that will maximise learning. It provides theoretical and empirical support for explicit models of instruction, in which teachers show students what to do and how to do it, rather than having them discover or construct information for themselves. Cognitive load theory is about optimising the load on students’ working memories to help maximise their learning.
The human brain can only process a small amount of new information at once, but it can process very large amounts of stored information.
Information is processed in the working memory, where small amounts of information are stored for a very short time. The average person can only hold about four ‘chunks’ of information in their working memory at one time.
Long-term memory is where large amounts of information are stored semi-permanently. Information is stored in the long-term memory in ‘schemas’, which provide a system for organising and storing knowledge.
If a student’s working memory is overloaded, there is a risk that they will not understand the content being taught and that their learning will be slow and/or ineffective.
With extensive practice, information can be automatically recalled from long-term memory with minimal conscious effort. This ‘automation’ reduces the burden on working memory, because when information can be accessed automatically, the working memory is freed up to learn new information.
Cognitive load theory provides support for explicit models of instruction. Cognitive load theory is supported by a significant number of randomised controlled trials. This large body of evidence indicates that instruction is most effective when it is designed according to the limitations of working memory.
Cognitive load theory indicates that when teaching students new content and skills, teachers are more effective when they provide explicit guidance accompanied by practice and feedback, not when they require students to discover for themselves many aspects of what they must learn.
Research from cognitive load theory has produced a number of instructional techniques that are directly transferable to the classroom. These include the ‘worked example effect’, which is the widely replicated finding that novice learners who are given worked examples to study perform better on subsequent tests than learners who are required to solve the equivalent problems themselves. Another finding is the 'expertise reversal effect', which shows that as students become more proficient at solving a particular type of problem, they should gradually be given more opportunities for independent problem solving.
Types of Cognitive Load
Sweller’s study went so far as to mention three types of cognitive load. These three categories make it easier for us, as teachers, to adapt our teaching methods to different learning styles.
1. Intrinsic Cognitive Load
Put simply, intrinsic cognitive load is just the difficulty of the subject, topic or information that’s being learned.
For example, single-digit addition has a lower intrinsic cognitive load for most than long division. You’ll notice in the example it says it’s easier for ‘most’, because the difficulty of a topic is subjective.
This makes intrinsic cognitive load difficult to control in mixed-ability classes, but it’s something you should still consider when teaching new topics.
2. Extraneous Cognitive Load
This is the easiest type of cognitive load to control inside the classroom. Extraneous load refers to the materials you use and the learning environment of your students.
Extraneous cognitive load takes into account the quality of teaching materials. For example, this could be how relevant the content is in relation to the topic, or the complexity of the wording in the teaching resource. It also accounts for distractions in the classroom that might affect students’ learning.
3. Germane Cognitive Load
The final type of cognitive load covers the moment when it all finally clicks. Germane load looks at when a student's working memory is able to link new ideas with information in their long term memory. It’s that ‘Eureka!’ moment.
If a student already has knowledge of a subject stored in their working memory, this makes the germane loading stage more effective.
But this also highlights the importance of balance. It’s important to consider each type of cognitive load equally, so pupils successfully transfer knowledge into their long term memory.
This is the moment when your children not only learn, but hopefully retain new information for life.
Teaching strategies from cognitive load theory
Cognitive load theory is supported by a robust evidence base which shows that students learn best when they are given explicit instruction accompanied by lots of practice and feedback. Through a significant number of randomised controlled trials (RCTs), researchers have identified a number of strategies that can help teachers to maximise student learning.
These strategies work by optimising the load on students’ working memories:
Strategy 1: Tailor lessons according to students’ existing knowledge and skill
Strategy 2: Use lots of worked examples to teach students new content or skills
Strategy 3: Gradually increase independent problem-solving as students become more proficient
Strategy 4: Cut out inessential information
Strategy 5: Present all the essential information together
Strategy 6: Simplify complex information by presenting it both orally and visually
Strategy 7: Encourage students to imagine concepts and procedures that they have learnt
You can download a free practice guide to cognitive load here.