It’s been a while since I’ve taken you on a tour of educational research. This week, I am offering you an interesting teaching strategy that deserves to be better known (it is not very well known, especially among French speakers…) and correctly practiced, because it is then effective. It is called in English the ” dual coding », in French the « double coding ». As a bonus, I tell you about an interesting research on this strategy and the supposed “learning styles”.
What is it about ?
This idea of double coding comes from the work of Allan Paivio (1925-2016), a Canadian psychologist. Simply put (I’ll provide reference texts for more on that), the idea is that in order to learn and store things in our long-term memory, we have two cognitive subsystems — two channels, if you will. — particular but related. The first processes visual information, and the second verbal information. This information is processed by working memory and then hopefully stored for later retrieval.
The important (and practical) idea is that if information is adequately and simultaneously presented in these two ways – visual and verbal – it is more likely to leave traces and be remembered. For teachers, therefore, what matters is that this combination of images and words is well presented.
How to proceed, then?
Double coding in practice
Let’s start with an example of a particularly incorrect — and therefore inefficient — way to do this: reading aloud text that simultaneously appears on a screen, as you’ve no doubt already witnessed with PowerPoint presentations. This produces what is called a redundancy effect, which overloads working memory, which is definitely not good for learning. The same bad effect occurs if one explains an image with text in it.
The aim is to combine what is presented in words (orally or textually) with a visual that illustrates, explains and concretizes the concept expressed. It is therefore necessary to choose this visual carefully; it must be relevant and must not overload the working memory.
In this regard, it is useful to remember that what is commonly called “the visual” can take many forms, forms that must be known and used judiciously. These can be graphs, diagrams, iconography, posters, drawings, sketches, briefing notes, etc. Each time, we seek to facilitate the transition from a concrete representation to a concept which is, by definition, abstract.
You can also involve students. For example, they can be asked to create a mental image of what has been taught — it can be a concept, a theater character, etc. You can also suggest that they make a diagram of a concept and its sub-concepts, thus creating a very useful concept map. They can also be asked to describe or comment on visual content.
I don’t have the space here to go into detail, but the articles cited below are worth consulting for more ideas on how to apply dual coding in the classroom.
I think that many teachers already have some idea of the effectiveness of this way of doing things and already practice it intuitively — it is, for example, the basis of illustrations in textbooks. The dual coding model confirms this intuition and offers more rigorous ways to implement it.
I don’t know if it exists, but it would be nice to have an accessible database of proven double codes, classified by subject and concept…
A search
Reading the above, some will make a connection with the learning styles model, for which there is no solid experimental evidence demonstrating that adapting one’s teaching to accommodate it does not bring any advantages. .
A study published in 2017 sheds some interesting light on this. She starts from this: “The double coding makes a contradictory prediction with that of the hypothesis of learning styles. Dual coding predicts that all learners should benefit from overlaying visual information with linguistic information. This contrasts with the prediction of learning styles, which suggests that auditory learners perform better when presented with verbal and linguistic information, while visual learners perform better when presented with visual instructions. »
The conclusion ? “The implications of these findings suggest that teaching based on learning styles is an ineffective method, but incorporating dual coding principles will be much more beneficial for student learning. »