Expert Insights

So I think we just, I used to give them, perhaps, 10 minutes to work on a problem, now I probably only give them two or three minutes.  I find that concentrates them and prevents them just talking about the State of Origin or whatever it is that’s on their mind.  We just need to keep changing the activity, rather than have extended activities... we want them to chat, but I think human beings won’t sit and chat about quantum mechanics for more than two or three minutes, they’ll get onto what they want for lunch.  So it’s that balance.

The actual curly arrow mechanisms are in a way themselves cartoons, how they map to the reality in the way that a Micky Mouse might map to real life.

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. 

So into the lectures I put kind of ad breaks, I suppose, short 'meet the scientist' breaks.  So we would have a photograph and fun facts about a scientist and various places we would have a stop, and I have told them that all of that information wasn't on the exam, so they knew that they could stop and just take a breather and then pick back up on the chemistry afterwards.  So that, I think helped, especially the ones that were just finding it all a bit kind of overwhelming. 

I have one slide where I'm first demonstrating how we use curly arrows and that shows an arrow going in a particular direction from a nucleophile to an electrophile and emphasising that the arrow shows electrons moving - so it's got to start from where they are.  There has to be some electrons there for them to move.  So the whole screen goes black and comes up with a little orange box of 'never do this' which is an arrow starting from an H+, which has no electrons. The dramatic emphasis that the whole room goes dark and then it's just up there.

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.

You could identify people and you use it in a constructive way.  But if you could show some identity, that you’re not a remote person up the front, that the big class is not anonymous, it just helps to break down that barrier.  And once they trust you and once they like coming, that solves a lot of other problems - behavioural problems, learning problems and so on.

Many years ago, lecturers only had one style, you know they just wrote on the blackboard, actual blackboard with chalk.  That was the only style.  They just talked... That’s all I knew so that was fine and so I thought, well I’ll just continue that and the students weren’t understanding what I was saying and explaining and I thought, oh hang on what’s going on here?  This is the way I was taught.  Come on, it should work.  So, yeah I think it would be good if someone told me that at the start, but as I said because I’d end up doing my Diploma of Education that opened my eyes to that and that’s when I started to utilise different strategies and I appreciate that not everyone is going to understand one way of, my teaching way.

I remember when I was taught this, that the only definition we were given was Le Chatelier’s actual definition, or his principle, and I remember reading that language and going geez, that’s really hard to follow as a student, so I used to always try and present that and then break it down in to a more simple sort of version that I thought would be easier to understand.

It’s continuous learning.  I mean, what I used to try to say to students when I taught the acid-base stuff I’d say ‘look there are only about six types of problems and if you can solve one of them you can solve them all because they’re all the same.’ But what you’ve got to be able to do is look at the question and say to yourself ‘this is one of those types of questions therefore this is the way I should think about approaching it.’  So take the question, dissect it, decide what you’re being asked to do, decide what information you’re given, and then say ‘yeah that’s one of those types of questions, this is the way I should go about solving it.'  If you can get that across to them, that it’s not a new universe every time you get a question, it’s simply a repeat universe of the same type of question... But many students tend to look at each problem as a new universe and start from the beginning again.  Many students don’t see that there is a limited number of problems that can be asked on a certain topic.

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