Two decades on, I still remember a couple of analogies from school science lessons, when my teachers would use one situation to help explain another. The atom, they told me, is like the solar system – electrons orbit the nucleus just as the planets orbit the sun. I also remember learning that electricity flows through an electric circuit as water flows through pipes – the battery is like a water pump, pushing electrons round to generate voltage, which is like water pressure.
Why teach with analogies?
Teachers use analogies like these to help pupils learn new concepts through comparisons with concepts they already understand. Children who know that the planets orbit the sun can use that knowledge to understand the concept of electrons orbiting the nucleus, for example. There can be benefits to learning by analogy, and adhering to certain evidence-based principles can make this approach more effective.
In a paper published in 2021, Maureen E. Gray and Keith J. Holyoak synthesised years of theory and research on teaching by analogy. While analogies are rarely perfect, comparing two situations that share common relationships among their elements can be useful in the classroom. Analogies can increase comprehension and reduce misconceptions. They may be particularly helpful for learning about concepts that cannot be seen directly – like the atom.
“Teachers use analogies to help pupils learn new concepts through comparisons with concepts they already understand.”
How to teach with analogies
Gray and Holyoak propose some guiding principles, supported by evidence, for teaching by analogy. For one, learners should already have a good understanding of the concept to which a new one is being compared. Teachers shouldn’t assume that all pupils already possess a good understanding of the original concept, even if it has been taught in the past, and a pre-test can help teachers gauge prior knowledge. A full explanation of the older concept can help ensure that learners have a basic understanding before the new concept is introduced.
When presenting the analogy, it is important to provide an explicit description of the common structure and the relationship between the two concepts. As Gray tells me, the teacher needs to “know like an expert but think like a novice”. Analogies may seem self-explanatory to adults, but “the information that jumps out to us is not obvious to novices”, she adds. Comparing and contrasting two concepts is a novel way of thinking for many students, and “explicit guidance from an instructor or a worksheet on how exactly to engage with the class material seems very important.”
“Analogies can increase comprehension and reduce misconceptions.”
Having both concepts visible at the same time, on the board or on a worksheet, may help pupils understand the links between them. Corresponding features might be colour-coded to emphasise the analogous aspects. Gray and Holyoak also recommend pointing out the limits of the analogy – irrelevant features or areas where the analogy doesn’t work – to help prevent misconceptions. Younger pupils need the most guidance, since they are more likely than older children to focus on superficial similarities.
According to Gray, the most important thing when teaching by analogy is to be “flexible and creative in adapting the use of analogy to best serve the teaching goals”. Classrooms are messier than lab studies, and teaching strategies that rely on analogies should reflect that reality. These guiding principles are not designed to be prescriptive, but to help teachers tweak the way they present analogies to meet the needs of their students. Analogies can be a powerful learning tool. Decades later students may find, as I have, that they still remember the analogies that were used to teach them certain scientific concepts.
How to use analogies in the classroom
• Fully explain the older concept before the new concept is introduced.
• Explicitly describe the common structure and relationship between the two concepts.
• Keep both concepts visible at the same time.
• Colour-code corresponding features of the two concepts.
• Point out the limits of the analogy.