Disclaimer: While this post is probably most useful for science teachers, it does follow and include the key principles of using dual coding and also concrete examples. Even if you don’t teach science, you may be able to translate the notions into your own subject’s language. So do not be discouraged and read on! Plus, it only takes about 5 mins to read this.
Dual Coding & Concrete Examples
Dual coding: just using images and speaking simultaneously in order to avoid cognitive overload, right? Can it be that simple? In essence, yes (well, probably not – these things rarely are!), but at its best it enables highly effective retention of knowledge .
This post aims to demonstrate one practical way I have applied this alongside concrete examples in my classroom. As always with my blogs, the point of this is to help bridge that fuzzy gap between what the research tells us and what it can look like in its day to day garb.
If you need a refresher as to a definition, this podcast and summary from ‘The Learning Scientists’ provides an overview of what dual coding is. There is also a link to a post from them on concrete examples.
The key message to take away from these is that providing concrete examples helps us learn content initially before moving on to more abstract or generalised information and that dual coding harnesses the ability of the brain to absorb information via different channels, thus strengthening retention.
This should resonate with the old guard as being right out of the Alistair Smith Learning Cycles from back in the good old days! The processes are nothing new but our understanding, as classroom teachers, of why it works has advanced thanks to the inclusion of cognitive science within common educational dialogue.
The Lesson Begins
All the lessons in my academy begin with a settling task; most involve retrieval practice to take advantage of the spacing effect and also interleaving to some extent (by combining questions from different topics within the subject).
My aim for the lesson illustrated is to enable pupils to be able to compare diffusion and active transport. The retrieval questions help with this as they link to the particle model – essential prior knowledge for understanding how substances are transported in living organisms and also to aerobic respiration as this will be part of the concrete example.
Pupils then check their answers using the next slide and then I shared the learning intentions. (Not objectives or outcomes!)
Story Time – Hook Them In and Make it Memorable
Following this, I aimed to beguile them with a story of why it is so important that we are mostly made of water – all living things are mostly made of water and that space scientists get really giddy when they discover evidence water may have been present on other planets as life as we know it depends so much on it. Therefore, aliens might exist!
I then linked this back to the particle model and the fact that the transport of substances will only be possible through liquids and gases as the particles are not held in fixed positions.
The Concrete Example
The key to a good concrete example for new content is linking it to something you know they know. Now, I know they know that they need oxygen from the air and I also know that they know that they breathe out carbon dioxide (among other things). They probably know that I know they know this too. Knowledge is king!
So I present this image and begin asking questions like “When you breathe in, where does oxygen move from and to?” Pupils respond using whiteboards.
We build up several arrows showing where oxygen and carbon dioxide diffuse from and to. The concrete ‘what moves where’ is established. Happily, this will help to reinforce prior knowledge using dual coding. A win-win situation!
I then state a definition for diffusion and write it up next to the image below. Having done this beforehand would have exacerbated the split-attention effect but this information will be germane to the next stage of the lesson.
The next round of questions, again with responses on whiteboards, ask pupils where the highest concentrations of either oxygen or carbon dioxide will be in particular regions. E.g. “Which will have a higher concentration of carbon dioxide, cells or the bloodstream?” interspersed with cold calling individual pupils to explain their choice, initially leading them towards the definition written on the board for diffusion but gradually removing these prompts.
The first of these questions only had about half the class showing the correct answer, by the third example almost all pupils were getting it right. Rosenshine would call this guided practice.
Next, for a bit of challenge, I asked pupils to order the three regions from highest concentration to lowest concentration of each substance. This was done independently, in silence, and about 80-90% were correct.
Often the best part of a story is the emergence of a problem. A challenge which needs to be overcome. Enter active transport.
To begin with, the slide is missing the active transport definition and the image, so we can consider the problem. “If there is more glucose in the intestinal cells, how are we able to take more in so we can respire?” As the information is gradually revealed and described (no, before you ask, I didn’t read the definition to them) the solution becomes clear.
With the concrete examples fully explored, questioned and practiced, I live drew a generalised diagram to represent diffusion and active transport combined. Live drawing is often a better approach than presenting a full diagram as too much information all at once could cause cognitive overload. Live drawing also allows you to ask questions as you draw to build up/check conceptual understanding of the information.
I began by drawing two near perfect freehand cubes. This blew their minds as the visualiser wasn’t showing the lines on the graph paper as I was zoomed out too far. Awe and wonder right there!
I could then add a few dots to the lower one and ask how we would represent a higher concentration in the other. The more questions along the way the better understanding will be. I then added short definitions for higher and lower concentration. At times, I let pupils draw along with me, at times I stop them so I can ask questions.
Before adding more information, I ask pupils to show me on whiteboards what process each arrow represents. This is where the dual coding kicks in. They are translating the imagery back into the keywords. (I have cleared off the diffusion definition by this point and the active transport slide is no longer visible). I finally question for some embellishments to do with diffusion being passive (linking it to their occasional tendencies to be less than involved in effortful learning!) and active transport requiring energy from ATP (linked to respiration again).
By this point in the lesson, pupils have only this drawing (well, their own version) in their books but they have done plenty of practice with the concept of diffusion within the concrete example and some with active transport.
Time to check performance with three key questions.
- What is diffusion?
- What is active transport?
- Compare diffusion to active transport.
Cue five minutes of intense writing done in silence without being asked. Then some model answers and a spot of purple pen self improvement.
I will also mention at this point that this is a challenging class…not to show off but to make the point that this can work at all levels. Even Y9 middle sets.
Next week will bring osmosis and flaccid potatoes. Yummy.
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