British educationalist Dylan Wiliam, says that Cognitive Load Theory “ . . . is the single most important thing for teachers to know”. Is it?
What is Cognitive Load Theory?
Cognitive Load Theory (CLT) was developed by John Sweller, an educational psychologist, and refers to the total amount of information that the short term, or working memory, can hold at any one time. The basic premise is that since the working memory has a limited capacity, teaching methods should avoid overloading it in order to maximise learning.
Most people have been on a course where the trainer has gone through the content so quickly that you barely learnt a thing, or have attended a session where the material was so complex that you left more confused than when you arrived. CLT offers explanations of why this happens, and what teachers can do in the classroom to avoid it and so maximise the learning of individuals.
What is Memory?
In our brains we have two types of memory. One is working memory, which we use to process new information. The capacity of working memory is quite limited so it can only handle so much before it is overloaded. Processing new information results in ‘cognitive load’ on the working memory, which can affect learning outcomes.
The second is our long-term memory, which is where we store information from our working memory and from where we can later retrieve that information.
In order to understand CLT, it is necessary to understand how the working memory and long-term memory process and store information.
Information in the working memory is stored for a very short length of time before being either processed or discarded. Research shows that an average person can only hold between five and nine items, or chunks, at any one time. When the brain processes information it categorises that information and moves it into the long-term memory, where there is endless capacity for storage. The long-term memory stores information semi-permanently, and works with the working memory to retrieve information.
Long Term Memory
CLT assumes that knowledge is stored in the long-term memory in the form of ‘schemas’. A schema organises and stores elements of information according to how they will be used. There is no limit to how complex schemas can become. It is a bit like a filing cabinet, so you will have a schema for different concepts such as dog, cat, mammal and animal.
You also have schemas for actions like hitting a ball, riding a bike, driving a car etc. The more you practice at using these schemas the more effortless these behaviours become.
An analogy used by those writing about CLT and the transferring of information from working to long-term memory is learning to read. At first we practice a lot to read individual letters as the working memory is small and information is not retained for very long. The simple schemas for letters are used to construct higher order schemas when the letters are combined into words, which, in turn are combined into higher order schemas for phrases and sentences.
Eventually, with ever more complex schemas, reading becomes an automatic or unconscious process requiring minimal conscious effort as the knowledge of how to read becomes part of the long-term memory. Schemas therefore reduce the working memory load.
Types of cognitive load
Cognitive Load Theory proposes that there are 3 types of cognitive load:
- Intrinsic Load – is the mental effort involved in understanding the content of a lesson, or a specific topic, and achieving its goals. It can be described as a ‘necessary’ cognitive load, e. g. learning to read.
- Germane Load – is the mental work put into creating a permanent store of knowledge, or schema, in the long-term memory, from the actual activities directed by the teacher.
- Extraneous Load – This is mental work imposed by irrelevant elements that require extra mental processing e.g. decorative pictures, animations etc. that add nothing to the learning experience.
How to reduce overload
- New material – Find out what your students already know before sharing new information with them, and then continually build upon their knowledge. Using metaphors and similes are good tools to help make links to information already in the long-term memory.
- Integrate visual information – Diagrams, such as a-maps, are a more effective learning tool than text. Incorporate labels into very clear diagrams rather than having them in a box at one side.
- Replace some visual information with auditory information – the mind processes visual and auditory information separately. Direct the student’s attention to parts of a diagram while talking about it and the burden on the working memory will be far less.
- Use worked examples – CLT follows the theory that learners do best when they are provided with step by step guidance clearly showing them what to do and how to do it, with teachers providing direction and support.
- Less is better - According to CLT we are less likely to overload the working memory when irrelevant information is cut out. So, remove decorative graphics and animations.
- Use more signals – Focus students’ attention and reduce effort by using concise writing, making every word count. Use bold text, bullet points and headings.
- Break content down – Break complex content down into smaller chunks and allow the student to control the speed of learning.
- Remove extraneous noise – cut out background music and reduce external noise.
Cognitive Load Theory is a developing field and an area of research with implications for teaching practice. It has some useful things to say about learning in general. By using the above methods teachers can test Dylan Wiliam’s statement!