Expert Insights

I guess what every educator deals with is needing to find out what preconceptions there are at the start of the unit and then correct those and then keep on top of those throughout the course.  For example I get students who use the word particle and the word droplet interchangeably. Whereas to an expert, a particle is something that is made of a solid material and a droplet is something that’s a liquid material.  Students use those interchangeably so they may be talking about a suspension of solid materials but then they use the word droplet because they think it’s interchangeable with the word particle. Or vice versa, they might be talking about an emulsion and they talk about particles where they should be talking about droplets.  So because they’ve heard these phrases before in first year... the importance of using exactly correct terminology hasn’t been reinforced.

When we’re teaching ideas in chemistry, I liken it to hacking your way through a forest.  It’s all this detail.... and you can’t expect students to do the hard work of fighting your way through the forest or the jungle, unless they have a global view of where they’re going. What I mean by that is, the other factors that influence the way I teach intermolecular forces, is that I keep going back to applications in the real world.  How is it that geckos can crawl up a wall, and almost sit on the ceiling without falling off?  How is it they’re able to stay there with gluey legs or what?  But the interactions between their feet and the ceiling are just, how could they maximise the attractions between the molecules in their feet, and the molecules in the ceiling? So what I’m trying to do all the time is to show applications, powerful, interesting, hopefully, and engaging applications of the ideas that are important. So, for students to engage and to feel, ‘well this is worth hacking my way through the jungle of detail to be able to understand it’, is to zoom out and show them how this topic relates to all of the other topics.  It’s called scaffolding, and it’s a very, very important idea. So, the other factors are essentially the incredible number of other applications of this idea... that the power of an idea is its explanatory power, and when they can see just how important an idea is, in being able to explain all sorts of phenomena, they might be willing to care about it more.

So the strategy is to reflect, to change things, to be flexible, to talk to them but not talk down to them, and certainly I would say to any young lecturer don’t be writing the lecture the night before. Know what your course is because then you can jump back and forth as you talk about something.  You can say yeah we talked about this a week ago or something like that, you know. Know what you’re going to talk about, the whole thing, because then you can put it all together as a package.

Difficulties are having to relearn something that they thought was true from school and not understanding the evolving nature of science. New knowledge is easier to assimilate than changing old knowledge.

In the lecture theatre the best strategy there, where you’re confronted by all the constraints of the lecture theatre, is to stop and do stuff with the students, walk around amongst them, see what they’re actually doing... And out of that you might go back and address some aspect of it and revisit it or something like that or you might point them to some tools to use to work out some other aspect.  So in the lecture theatre it’s very much for me a case of stopping and going and seeing what they’re doing and if you don’t then clearly you don’t know. 

Students see equations and panic. Students struggle to transfer mathematical knowledge to chemical situations. Students silo knowledge and find it hard to relate concepts to actual systems.

It’s something that needs to be reinforced, it’s not that you taught it in this unit for three weeks, we are over it. It’s something that keeps coming back, and that you can possibly reintroduce it, with not much change to your teaching. Not every single time, but every now and then remind the students, ‘remember, you still have to think about stoichiometry and limiting reagents’.

It was a revelation to me in second year when [one of the top professors] said to me, "Buy a model kit." And so now I tell all my students.

It now does come down to the quality of the presentation in terms of what you put on the PowerPoint I suppose, cos we all use PowerPoint.  But I try most lectures to switch that off and use the visualiser and write things down by hand, where I can see that something is missing on the PowerPoint, or if I think the students haven’t got a particular message, don’t understand a reaction, don’t know about a mechanism. I’m happy to stop, go to the visualiser and write it down at the correct sort of pace, by which they can actually write it down themselves.

I like to approach chemistry as a different language, because it used symbols to convey ideas across, but they are not the reality.  When we draw a little stick structure, alcohol does not exist as I’ve just drawn it, it’s a representation.

Pages