‘Cognitive load’ is described as the volume of information that the brain can absorb or ‘take in’ at any one time. Our working memory. Overload it, and you, or your students, won’t remember much beyond that point. Dual coding can help.
Dual coding recognises that there are two ways in which the brain can receive information – graphically and textually (or verbally). Each are stored individually, but the connections between them gives the brain two ways of finding the right information instead of just one. How many times have you looked for some information on a page of a book, remembering only that it was in the bottom right, in a green box, with a picture, for example? The same is true for students too. Sitting in an exam, they now have two methods or recalling exactly what they need to answer the question.
In the classroom, dual coding can be used by:
Reducing the volume of text to simple bullets – We can then talk around these points
Align the content rather than using randomly placed textboxes
Choose one or two calm colours and simple fonts
Provide a strongly related image to help bind the text with the visual
Dual coding helps move things into long term memory and speed up the retrieval of such things. A win-win when your exams are still more than a year away.
Graphics for learning
Illustrations certainly brighten up any classroom slide or textbook page, but they must be used sparingly and thoughtfully. To help dual code the written content, they must also be as closely linked to the topic as possible to aid learning and if they can harness emotion, so much the better. Anger, sadness, joy and fear are some of the strongest emotions. Look at the sad image of deforestation in the third page below for example – Does this help you to create a memory, even without reading the text?
Diagrams also help. “A picture says a thousand words” certainly has truth. Words need to be processed one at a time as they are read. Images on the other hand, can involve multiple aspects, all of which can be simultaneously absorbed and processed.
Visual engagement and motivation
Using images to dual code helps us learn. Learning feels good and so our motivation to learn increases. Images and diagrams can help stop monotony. Design each slide, or each page of a booklet for example, with a unique style and presentation. Avoid using the same layout for every page or slide. Have something new at every turn. Always break up a full page of text with an image or diagram. Vary the angle of view. Use soft colours to help accessibility and leave plenty of white space.
Try it all out in presentations, booklets, worksheets and homework exercises. Remember though – less is more. Too much clutter and randomly arranged objects will upset the perfect balance.
Allan Paivio first proposed the dual coding theory in 1970.