I have been using bar-model incidentally in my year 11 revision groups for a couple of months now. I usually just sketch the bar while I’m explaining. This example was from a radioactivity question.
In the past I would have written this as an equation:
measurement = source + background
But the bar-model seems to cut through to the meaning faster. My students look at the bars and nod. And then they answer the question.
I have a couple of explanations for this. Today I want to write about dual-coding (the next blog will be about reducing extraneous cognitive load using bar-model).
Dual-coding is when we combine an image with verbal information. This has been shown to improve long-term recall. So in this example, as I describe how to calculate the source count, I am pointing to the bars instead of pointing to an equation.
When I used to point to the equation while I explained, I was combining words with words, overloading the working memory (see and hear LearningScientists here).
If you like bar-models, a group of science bar-model pioneers have begun to upload our blogs and tweets here.
In my next post I will explain how bar-models reduce cognitive load for learners.