Teaching with analogies – Science-Education-Research

A topic in teaching science

Teaching is often about making the unfamiliar familiar. The unfamiliar may be something quite abstract such as magnetic flux density, oxidation state, or genes. One technique commonly used in introducing unfamiliar ideas is to suggest they are in some sense somewhat like something that is already familiar by offering an analogy: perhaps that atomic energy levels are like the steps on a step ladder or that the telomeres on chromosomes acts as protective caps like those found on shoe and boot laces. Such comparisons are usually very limited – the two things match in some senses but not in others (Taber, 2001). Because the aim is help learners understand the scientific idea, the analogy is meant only a temporary aid, a form of scaffolding that will be discarded once no longer needed.

We might consider the teaching analogy as being a bit like a reaction intermediate in a chemical reaction:

"So, teachers use analogies, metaphors, similes and similar verbal devices as well as models and representations of various kinds…but there is the danger of learners developing new alternative conceptions if they take comparisons too literally or misread which features of the familiar 'anchor' are meant to transfer to the novel material. … Generally using these types of familiarisation devices is a very good way to help learners become familiar with novel and often abstract chemical concepts. But it is important for teachers to both (a) be explicit about the differences as well as the similarities (even if the differences may seem so obvious to a teacher that they do not seem worth mentioning) and to (b) see such devices as transitional – perhaps like reaction intermediates that we do not want to be our final products – and move on from them as soon as learners are comfortable with the new ideas. That is, when what had been unfamiliar has become familiar and unthreatening.
…I will assume I do not need to spell out those ways that reaction intermediates are actually quite different from the metaphors, analogies, similes, teaching models and the like that are used to make new ideas familiar. It may be that making such 'obvious' points in a class could seem condescending, but this is less likely if the matter is posed as a question for learners, which then also offers the teacher feedback on how the comparison is understood: for example,

Can anyone suggest to me any ways in which a chemical equilibrium is not like two children balanced on a seesaw?

In what ways are energy levels in an atom not like the rungs of a ladder?"

Taber, 2024

Teaching with analogies then, involves:

introducing an analogue which has parallels with the idea to be introduced, and which is already familiar to the learners;
making it explicit which features of the analogue are of interest because they are relevant to the analogy, and showing how these map across to the scientific idea being introduced; also, checking that learners appreciate that salient but irrelevant aspects of the analogue are not being transferred to the 'target' scientific idea;
judging when the new learning is sufficiently familiar to learners that the analogy can be discarded

Here is one example of how this might work, using a paired concept map to represent an analogy that has been used to explain a scientific concept (telomeres). Paired concept maps, as in this example, may be useful tools that the teacher might use to clarify her own ideas, or actually present in teaching, or ask learners to draw to demonstrate understanding of ideas being presented.