Expert Insights

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.

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.

Chemistry is a different language so I try to approach it that way by explaining the ideas behind symbols.

I think it’s really important that people mark assessments.  Mark, and see what the students actually end up knowing.  Because they can pretend to themselves that students have understood everything, but if they actually have to mark the exam papers, or the quizzes, or whatever it is, they actually are confronted with the students actual knowledge.  I think that’s really influential.  The second semester of teaching, when you think you’ve explained things well, and then 90% of the class have not got it, then it’s not the students fault at that point, it’s probably your fault.  So I think that assessment is really important.  Not only for the students, but also for the marker.  I think you can learn a lot from marking.

But if you’re honest, they’ll be honest right.  And I think that’s really important. If you b*gger something up and you really do make a blue or even a little blue, tell them.  Say ‘oh look this was wrong, you know this is what it should be’.  So that’s important - to be honest, to be upfront.  Recognise that we’re dealing, in 2015 or 2014, we’re dealing with OP1 to maybe 14. Recognise the breadth of that class. Don’t teach the top, don’t teach the bottom, teach somewhere in the middle, but try to make sure that you don’t lose the top ones and lose the bottom ones, which is very difficult to do and you only do it with experience.

I think we’ve all sat in lectures and gone, that was dreadful, so we learned quite a lot from understanding how not to do it as well as how actually to do it.  And of course the key is preparation and organisation..... whenever I go into a class knowing that I am beautifully organised, that gives you that extra confidence to project and to present, and you come away with that feeling that you know that the class has gone well and you’ve got the information across to the students in the way that you wanted. 

In the workshops, the workshop idea as we run them is that you are out and about and amongst the students all the time in those groups, seeing what’s going on in the groups, seeing how they’re answering their questions.  They have set questions on sheets that they work through in groups and the groups of three just get one set.  They’re all working on them together and you’re moving in and out and around among the groups and seeing how they’re going.  In that circumstance you can quickly, having looked at three or four of your eight different groups, figure out where a particular issue would be and then that can be addressed on the board, it can be addressed with models or something like that.

At the start of every class my standard thing was ‘can you see me, can you hear me, can you see the slide?’ I would always look up the back for someone to put their hand up and always I would never talk to the front row. I’d always talk middle and back row and if someone was talking in the back row I’d pick them up and say ‘hey you, be quiet’ and then they know that I’ve seen them.

So you’ve got to focus on the whole class not just the people at the front - the people at the back as well.  Because sometimes smart people sit at the back as well, not just the dummies who want to get out. You’ve got to make sure you know everyone in the class.  And the surprising thing is that most kids sit in the same place every lecture.

So you can actually recognise where they are and who they are.  You don’t know their names but there’s a pattern in the way they sit.  You’ve just got to be aware of that.  So the trick is to embrace the whole class with your - you know physically, just with your eyes and and the way you talk.  You know, when you wave your hands, wave it to the back row. Make sure they’re involved.

They [students] reveal great misunderstandings about the molecular world. So the difficulties and limitations are as a result of not spending sufficient time on getting them to think about this world, and spending too much time on doing. You know, we’ve got to spend some time, but you can’t spend too much time, I think, on a lot of the ideas that we do teach, and doing calculations and things that, really, no one else does. It’s really something that’s done almost like it’s make-work-type stuff.

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.

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