Most of the people reading this blog have some knowledge of chemistry and/or biology. (Not everyone, though – I get email from readers with no formal training who just stop by to hear what’s going on, and I’m very happy to have them). But if you do know a lot about a subject, any subject, you’re almost certain to have trouble picturing what it’s like for someone who doesn’t. That includes trying to anticipate what sort of misconceptions they might have, or errors that they might make. It’s almost impossible to pretend to unlearn something in a way that’ll let you do that.

This is a well-known problem in teaching, naturally enough, and one part of being a successful teacher (at any level) is knowing what sorts of conceptual mistakes students are most likely to make and recognizing them when they show up. Even those of us who didn’t go into academia got a taste of this while being teaching assistants in grad school. I remember doing a lab lecture about thin-layer chromatography, with illustrations on the board, before handing out those aluminum-backed TLC plates for the sophomore organic lab section to use. I was baffled when two of the guys in the class couldn’t get any spots to show up. They tried again – no spots, and these samples were the sorts of organic compounds that will give you bright, well-defined spots by TLC. Finally, I watched them apply the test mixture to the TLC plate – to the aluminum side of it, rather than the white powdery silica gel side. After I got through rolling my eyes, I had to admit to myself that I hadn’t anticipated that one; it was an error that it had never occurred to me that anyone could make. But there it was, right in front of me. After that, when I told anyone how to do TLC for the first time, I always worked in a quick mention of the difference between the two sides of the plate.

This article by Ed Yong over at The Atlantic got me to thinking about these sorts of errors. He’s summarizing a recent survey (PDF) in the UK by the Wellcome folks about antibiotic use. They found, of course, that the general public doesn’t have much idea how antibiotics work, and are mostly lost on the difference between antibiotics and antivirals. Those I already knew (discussions with relatives and so on). But this survey turned up another misconception that falls into the same category as my TLC plate one above, something that I never would have thought of on my own. It turns out that when asked about antibiotic resistance, many people thought that the problem was that their own bodies were becoming resistant to the effects of antibiotics. Therefore, you know, not finishing a prescription course of one wasn’t such a bad thing, because it probably kept your body from becoming resistant to it. (This, of course, is the opposite of what you should actually do)

The survey people tried various ways to get across the actual situation, that it’s the bacteria themselves that are becoming resistant, and had some success. The Wellcome Trust itself now says that they’re not using the phrase “antibiotic resistance” now, and they refer to “drug-resistant infections”, for example, to make the causality more clear. Showing people pictures of actual bacteria also seemed to help them connect the ideas, probably because bacteria in general can be a sort of invisible abstraction if you’ve never spent much time in front of a microscope (or reading articles by people who have).

That by itself is not going to turn the public health problem around, although it certainly won’t hurt. The larger point, though, remains the same – that we don’t always get the scientific messages across that we’re trying to, because (1) most people aren’t scientists, and (2) because we are. Something to keep in mind.