Cognitive Load Theory
Cognitive Load Theory (CLT)
How Your Brain Learns (and how we design for it)
Have you ever wondered how your brain learns?
Cognitive Load Theory (CLT) has the answers.
CLT is a robust instructional theory that provides a powerful framework for designing instruction that aligns with how human brains work.
So, what are the core concepts of CLT and how do they help us create e-learning that works?
Settle in, because this is a long one. We’ll cover:
Part 1: Making Memories
Cognitive Load Theory (CLT) was pioneered by John Sweller. It's built upon three fundamental ideas about how the human brain processes and stores information.
Learning something new requires us to organise it in our long-term memory; but that's easier said than done, as there are two gateways before the information can get there.
Our brains have limited working memory capacity, so they need to 'filter out' most input.
Sensory Memory
The filter
Your sensory memory is a filter, that blocks out most of what is happening around you, so you can concentrate. The sensory memory passes (hopefully useful) information on to your working memory.
Working Memory
Active mental workspace
Your working memory is the active mental space where you consciously process new information. You’re processing this information about CLT in your working memory right now.
Long-Term Memory
Your vast knowledge warehouse
Your long-term memory is your "big mental warehouse", where you store all your knowledge, from simple facts to complex ideas and skills. Long-Term memory has virtually no known limits to its capacity or duration: the challenge is getting information in – and out!
Your Limited, Active Mental Workspace
Everyone’s working memory has limits to its capacity and duration – because we’re human.
Overlaod
Working memory is a precious resource. Overloading this limited workspace slows down learning. Information gets misinterpreted or confused, and it’s harder to transfer it into your long-term memory.
Capacity
There are two key variables here: how much you need to learn, and how familiar you are with the topic.
Research suggests that an average person can typically hold only 3 to 5 items of new information in their working memory at once, and only for a very short time. (George Miller suggested we between 5 and 9 ‘items’ (7±2) in 1956, but some of the items Miller asked people to remember were ‘chunk-able’ (easier to remember, because they're related.)
However, your capacity also depends on how much you already know about the topic - it's easier to add new knowledge to a solid base.
Input streams
Our working memories have limited capacity; but there's more than one way for information to get in.
Our working memory has partially independent processors, or ‘streams’, for our senses. Of course, in relation to learning, we're realistically focusing on visual and auditory information.
The auditory and visual streams operate somewhat independently of each other, and don’t directly compete for the same limited resources.
More about these later …
Part 2: Building Knowledge
Schema Construction and Automation: The Keys to Expertise
Our brains organise information in our long-term memories into ‘frameworks’, or 'schemas'. There are two stages: construction and automation.
Schema construction
We construct schemas by actively making our working memory process the new information. Active processing in our working memory integrates the new information into our long-term memory as part of a schema.
Schemas group related pieces of information into single, organised units, based on how we’ll use them. The key point is: regardless of its complexity, a schema counts as only a single element (or chunk) in your working memory. For example, the word 'memory' contains six letters; but you have a schema for it, so it registers as one item, freeing up your working memory to process other information.
Building increasingly complex schemas, by combining lower-level schemas into higher-level ones, results in more skilful performance.
So, why did I ask you the question about 3-5 items of information?
Well, the more you use your schemas, the more they develop, and the easier they are to remember.
Would 3-5 be as fresh in your mind, if I hadn’t asked?
Schema Automation
If you use your schemas repeatedly, it gets easier to access and manipulate the information they contain. With practice, you can 'automate' these schemas.
Automation makes it even easier to process and retrieve information, because you’re already very familiar with the content and its application. Automation further reduces the burden on your working memory, increasing your capacity to learn new information.
Part 3: The Blueprint for Effective Learning
Learning is work: it imposes 'cognitive load' on your working memory. Trying to process too much information at once causes cognitive overload, which reduces understanding and blocks your learning.
Managing cognitive load is the key to effective learning.
Let’s examine the competition.
Extraneous Load
What is extraneous load?
Extraneous load is ‘extra’, unhelpful cognitive busywork, that distracts, confuses, or makes it harder to construct schemas.
Effective instructional design rigorously eliminates or minimises extraneous load to free up working memory capacity for actual learning.
Reduce extraneous load
Overloading the working memory inhibits learning. Cut the cognitive busywork by:
✔ Removing Redundancy: Avoid presenting unnecessary or redundant information, like reading text that’s already on a slide.
✔ Eliminating Attention-Splitters: Keep related information sources (e.g., labels on diagrams) together, so learners don't need to combine separate pieces.
✔ Leveraging Modality: Present complex, non-redundant content via both visual and auditory channels (e.g., diagrams with spoken text) to leverage both working memory streams, and increase processing capacity.
With extraneous load taken care of, we can move onto making learning happen.
Intrinsic Load
What is intrinsic load?
The intrinsic load is the inherent complexity of the subject matter itself. Intrinsic load is necessary: it can’t be eliminated without compromising understanding.
Two factors are key here:
- the material's 'element interactivity' (how many elements you need to process simultaneously), and;
- your prior knowledge.
Manage intrinsic load
Effective instructional techniques can manage Intrinsic load, for example, by introducing new information gradually. Balance the inherent difficulty of the material against what learners already know:
✔ Assess Prior Knowledge: Understand learners’ existing knowledge to get them to where they need to be, starting from where they’re at. <test-out or Test-Teach-Test can do this>
✔ Break Down Complex Problems: Divide large, intricate tasks into smaller, manageable parts to avoid cognitive overload and help learners process complex material.
✔ Employ Simple-to-Complex/Part-Whole Approaches: Introduce material gradually, starting with simpler elements, before building to full complexity.
Germane Load
What is germane load?
Germane load is (now) defined as the working memory resources we devote to dealing with intrinsic load , so we can construct and automate schemas.
(The concept of germane load has evolved, from an ‘input’ to an ‘output’. Originally, germane load was considered to contribute directly to learning – it was conceptualised as the load of ‘doing learning’, or ‘performing the process of learning’. However, extraneous and intrinsic cognitive load explain all the available data; germane load doesn’t have a visible effect on learning, so it’s no longer considered an independent source of ‘load’.)
Germane load
Understand learners’ expertise, and help people build schemas.
✔ Facilitate Schema Construction: Design instruction to actively support schemata building and abstraction, as this process is central to effective learning and is where working memory resources are productively directed.
✔ Support Automation through Practice: This is the technical answer to why I asked you the ‘how many items of information?’ question. You automate your schemas by practicing extensively: automation then frees your working memory to focus on learning new things.
Summary
CLT helps us understand how our brains process knowledge and learn. Aligning instructional design with what we know about the characteristics and limitations of human working memory promotes more efficient and effective learning.
Effective instructional design:
✔ reduces extraneous load
✔ manages intrinsic load, and
✔ enables us to use our working memory resources to construct and automate schema (which is what germane load now describes).