Expert Insights

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’.

So the first thing that I really stress that people do, is that they actually go and watch some classes.  I think that’s the most important thing.  When they’re coming straight out of a post doc, or they’re coming straight out of the Research Centre, and then, they’re told they’re going to be lecturing 300 first year students, they’ve got to go and sit in the back of the lecture theatres for a few weeks.... when I came over from the UK to here, and the class sizes are about three or four times as big, it was just a real help to be able to see what worked and didn’t work  – how little time the students were on task in quite a few lectures.  Where the lecturer would just be talking and be oblivious to this.  I think people just learn a lot by seeing good things, but they also learn a lot by seeing quite bad things going on.

It is vitally important for their understanding of chemistry that they understand that molecules are three-dimensional things and that they have a spatial requirement in that they have a shape of their own and that shape will change.  They can't do higher level manipulations without an understanding of three-dimensional nature of molecules.

The culture in the chemistry department was always lots and lots of content.  And that’s changed now because you don’t need it, because they can find it another way, but you’ve got to give them the framework to understand the content.

The difference between chemistry as it happens in a flask, chemistry as we show it on paper or in a textbook and helping students to understand that these are representations and they're conceptual frameworks that we use to understand our discipline and so helping them put those two pieces together.

I find it [teaching] enjoyable, and I think that if you’re enjoying teaching something then your passion and desire and enjoyment gets transmitted to the students.  It’s not necessarily easy to teach, but it’s satisfying and generally we want to inspire them to increase their level of intrinsic motivation to want to continue to study chemistry.

I started lecturing before I did my Diploma of Education and I would have recommended to all of the lecturers to do it because it really helped me in my teaching.  Mind you, I already had a bit of experience, I don’t know, you know, the chicken or the egg type thing.

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.

When you think of things in terms of energy you can represent energy … energy can be modelled as a particle, as matter.  It can be modelled using waves and then trying to talk about how we would use each model as it's appropriate for a particular situation.  It's the sort of things we observe might dictate which model we use to explain it, by recognising that in each case there is another model but perhaps just not as useful.  So maybe it goes back to just trying to show that everything that we do is a model, every model has its upside and its downside and that we usually only use a model that’s as detailed as it needs to be for the particular concept that you're trying to get across.  If you want to get across a concept of a car to someone who has never seen a car you don't probably show them a Ferrari or a drag racing car.  Maybe you show them a Lego style block and we do the same thing with our scientific models as well.  I guess trying to get across that idea that this is the model that we're going to use but it can be a lot more complicated.  I don't want you to think it's as simple as this but it's appropriate under the circumstance.  So I guess I spend a lot of time talking about things as models when I'm talking about quantum mechanics.  Our treatment in the first year, which is where I cover it, a little bit of second year but I don't take a mathematical detail treatment of quantum mechanics.  Someone else does that, so I really bow to them. So most of mine is non-mathematical, just simple mathematics and mainly conceptual type of stuff.  I guess some of the things I try and do to illustrate the differences between the models and the way that we use them is to ask questions in class that might be postulated in such a way that you can't answer it if you're thinking about both models at the same time.  So the one I like is where I show say a 2s orbital and the probability distribution of that node in between.  I talk about things that … there's one briefly, this plum pudding model which they all laugh about.  When you look at this 2s model there is a probability and a high probability, relatively so, that the electron can be inside the nucleus, if you think about it in particle terms.  Then talk about the nodes and so on and how they arise in quantum mechanics and so on and then ask questions like if the electron can be here and here but it can never be here how does it get there?  ...  I try and get across maybe the bigger picture, everything we're going to do from this point on (because we do this fairly early in first year)  - everything is going to be a model.  Nothing is going to be right.  Nothing is going to be wrong. Nothing is going to be exactly the way it is.  Everything will be just a model. You'll hear us saying things like ‘this is how it is’ or ‘this is what's happening’.  But really you need to interpret that as ‘this is a model and this is how this model is used to explain this particular phenomenon.

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. 

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