I recently read a popular science book on a topic that I felt I needed to learn more about. The book was well written, ideas were clearly explained, and I finished the book knowing a lot more about the history of the subject than beforehand. However, I don’t feel I understand the key ideas in the book any better. I won’t mention the name of the book or the author because this post isn’t really about that specific book. It’s about how I feel books of this nature often fail to deliver on what they implicitly promise: that you will understand the science contained within their pages.
There’s a notion among many science communicators and, I suspect, science teachers, that if you can simply come up with a clear enough explanation for something in science, then your audience or students will understand it. I don’t think this is always true.
I think listening to or reading a clear explanation of a scientific concept can be the first step towards understanding it, but real understanding only comes with trying to apply the explanation to a situation or phenomenon that is different to the one in the explanation given. In other words, I think a key test for understanding a bit of science is that, as my friend Ben Craven puts it, “your knowledge of it is such that you can do things with that knowledge in circumstances other than those in which you first understood it.”
Let me give you an example: All year 7 students (11- and 12-year-olds) are supposed to learn about the particle theory of matter – the idea that everything is made of particles (atoms or molecules) and that the more energy these particles have, the more they move about. This, they are told, explains the differences between solids, liquids and gases and they might be shown a diagram like the one below:
It’s a deceptively simple sounding idea. Yet, every year, I encounter new A-level students (16- and 17-year-olds) who are incapable of applying these ideas when answering questions in class or in tests. And that tells me they haven’t really understood it.
When they are taught about the particle theory of matter in school, students might be shown animations or be made to run around the playground pretending to be particles. They might also be shown demonstrations of a tin can being crushed by air pressure or how a ball of metal will not fit through a hole once it has been heated up – both things that you might also see in a “live science show” done by a science communicator who might also throw in a demonstration or two using liquid nitrogen. But a live science show, or indeed a popular science book, will miss out what I think are two key elements of the teaching process: discussion and assessment.
It is only through asking our students questions, first in classroom discussions and later in tests, that we give students the opportunity to try out their understanding. And it is only through observing them do this that we, as teachers, can make any judgement about the extent to which they have or have not understood whatever it is we’ve been trying to teach them.
“What do we want a student to be able to do to show they have learned the things we want them to learn?” This is the question that the The University of York Science Education Group is asking at the heart of its new project to develop resources which will “check students understanding of all the important ideas in KS3 Science”. It’s a question all science teachers should ask themselves as they plan their lessons, and perhaps a question some science communicators should ask too.
Image: Phases of matter. Credit: besmayweather.weebly.com