My students in Terminale (final year of high school) had a chemistry test today on acids and bases.
In the past I’ve always enjoyed tests and exams that are so conceived that by the end of it you’ve learned something new. When I can, I do try and make tests of that nature, though obviously it’s not an easy thing to do (at least when it comes to chemistry for me, where I’m much less intuitive than physics), and quite time consuming.
I nevertheless try. Such was the case for the test this morning. For those curious, the idea of this test was to lead them down a path where they would see that a weak acid behaves more and more like a strong acid the more it is diluted, counterintuitively to what we’ve seen in class (important point).
One of the very first questions was, therefore, asking them to make a hypothesis about various aspects of the behaviour of the acid, based on what they’ve learned in class; the objective being to show by the end that this hypothesis is actually false, counterintuitive though it might seem.
As they were working I started to walk around the class to see how they were doing, as one does, only to find, much to my surprise, that many were leaving the hypothesis question blank! I simply assumed they hadn’t really understood the question or weren’t very sure of what they were expected to say, or simply that they simply hadn’t learned their lessons well enough.
It was nevertheless surprising to see even some of the better students doing this (if anything, it was mostly the good students who were doing this!).
“Il vous reste dix minutes, finissez le travail!” I announced and started to navigate around the classroom, checking to see if all is well, and that is when I was once again shocked to see they many of them were now going back to the hypothesis question, and answering it, having found the final result!
Once I’d managed to pick up my jaw from the floor, I announced the end of the test and collected all the papers, with a couple of minutes remaining before the bell.
I had to ask them, what the heck was that all about.
The answer was unanimous “well we didn’t want to give the wrong hypothesis!”.
In hindsight, I should not have been so much taken aback by this answer, but I was shocked as much by their sincerity as their error in their thinking about the problem. I didn’t hesitate to tell them that what they did was basically about as unscientific as it gets. To which they mostly shrugged as they packed their stuff, save for the one or two who, as usual, stubbornly tried to defend their way of doing things.
As a teacher, as a scientist, or as anyone with any sense of reason or history, there are so many reasons to be upset at this mindset. The most obvious one is the whole idea of the “scientific method”, i.e. question, hypothesis, experiment, observation, interpretation, conclusion process is literally the first things we talk about when these kids first start to physics in cinquieme (grade 5).
I know I insist on it, and try and go into details about how we can apply this as much to something simple and evident as we can to something complex and cosmic. It is the pillar on which modern science is built, without which we’re just keeping busy collecting stamps.
And yet the more I think about it, the more I have to admit to myself, that should be the farthest thing from surprising, given all that I’ve seen in my years of being a teacher.
