Analogies and Multiple Explanations

Resources, ideas and prompts for discussion related to Explanation

Making complex ideas easier to understand

If you compare a new concept to an idea already safe and secure in your listener’s mind and knowledge there is a great chance they will understand it quickly. This is where the power of analogies can be the turbo charger for teacher explanations. As long as your listener has some prior knowledge of what the analogy is referring to then we are in with a chance (on this point we can emphasise why having strong knowledge of your classes is crucial).

Taking a couple of examples from Science (though analogies work in all subjects), for an analogy to be successful the narrative must take the learners from the concrete to the abstract and arise when the base idea and the new target idea share relations in meaning. For example GCSE Science students may learn about an enzyme’s active site and a substrate being complementary and ‘fitting together perfectly’ when compared with a lock and a key (which often works because students almost always know how a lock and a key fit together). Good analogies are simple, easy to remember, and based on familiar analogous concepts. To make analogies even more effective it is important we then accept their limitations and point out where the base and target idea differ (for example a lock and key are rigid structures, but an enzyme and substrate can ‘mould’ their shape around each other, a bit like how a sock and your foot adapt to the shape when they combine…and therein lies another analogy!). It is always important to make sure the importance of the new knowledge is then emphasised, else you find students write a wonderful explanation of the analogous information instead of the curriculum content in an exam!

Really thinking about analogies in your curriculum

If you want to really go to town with analogies in your subject area then they can be planned for and prepared with a simple checklist so that you know you have all bases covered. This is shown in the table below using a different example of comparing the structure of an atom to a sport stadium. Some have used this same checklist type approach as a lesson task where learners fill in the boxes as the analogy and explanation progresses, or as they learn more.

The new knowledge aka. target ideaWhat is the key idea/big picture?Structure of an atom
The analogyWhat analogy could explain this?A grain of rice placed in the middle of the pitch, and an empty stadium except for a speck of dust in the outermost row of seats.
The similaritiesHow does this relate to the target idea?The grain of rice is like a proton in the atom’s nucleus.
The speck of dust is like the electron.
The whole stadium is the Hydrogen atom.
Stickability!What key points do you want to stick?That electrons have very little mass compared to protons.
Electrons are found on the outside of atoms.
Most of an atom is empty space (between the nucleus and the electrons).
The differencesHow does the analogy differ from the target idea? Points that could reinforce the new idea.Atoms are 3D.
Electrons can move and orbit the nucleus, the speck of dust is still.
The space between the rice and the dust isn’t really empty space (there is grass, seats, signs), in an atom it would be a vacuum.
Considering and structuring an analogy to ensure it has as much impact as possible in explaining a new concept.

How many explanations will I need to use?

Every person that you’re speaking to in a room will have different prior knowledge, even if slightly, different experiences, and perspectives. Therefore one explanation is sometimes not enough as a one size fits all, and providing more examples and strategies is going to improve success rates. As teachers we tend to have a lot of pride in what we have said and the way we have said it, but we need to do our very best and leave our ‘expert ego’ at the door and if a learner really fails to understand what we thought was a masterstroke explanation, then don’t lay the blame at their feet if they had been listening attentively. Our patience, perseverance and wealth of knowledge is what will make the difference. Consider this example related to Geography and the formation of glaciers from ‘Making Every Lesson Count’, there are several explanations that could be used (one or many may have the desired impact):

  • Using a concise description linking to prior knowledge – about a slow moving river.
  • The teacher using a physical analogy, with students lined up at the front of the class creeping forward very slowly, gets a student to join the line every now and again at one end representing the zone of accumulation (where snow will fall), and removes a student at the other end representing the zone of ablation (where the glacier melts).
  • A selection of images and diagrams displayed on screen to point out and illustrate key facts.
  • Questioning used to target and test common misconceptions that they are aware of (such as the apparent appearance of glacier retreat even though it is still moving forward).

If none of these are successful it provides us further opportunity to re-plan and consider what else have we used or seen that could make the new idea stick. As mentioned in the introduction section on Explanation, it can be a very difficult skill to master but is arguably one of the most effective means of securing progress in learning.

Associated further reading and references:

  • ‘Chapter 2: Explanation’, in Allison, S. and Tharby, A., 2017. Making Every Lesson Count. Carmarthen: Crown House.
  • Brown, S. and Salter, S., 2010. Analogies in science and science teachingAdvances in Physiology Education, 34(4), pp.167-169.