Expert Insights

The concept of a continuum is, I think, really important in chemistry and… what I see is that students come up with this issue of things being black or white.  They struggle with this concept of the in between stuff.

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. 

A lot of it is from colleagues.  Conferences are fantastic.  You know, your chemical education conferences.  I do go to a lot of those.

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.

We do an awful lot of focus on teaching but realisticly, authentic assessment that actually engages the student, that’s a tougher ask... I set a lot of essay type assignments. I think we ought to do more of that in science.  But when I started doing this I used to get very poor results and it’s taken me a little while to realise that the students weren’t understanding what the questions was.  They didn’t understand what I meant by compare and contrast or discuss or argue for this.  So increasingly now I use workshops to actually spend time with the students unpacking, what is this essay assignment about?  What am I actually asking you to do?  What do you need to think about? And not assuming that they know how to write an essay.

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.

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.

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.

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.

I was thinking about Le Chatelier’s principle and how that’s quite cumbersome in its wording, and so when I teach it, and how I always break that down into language that’s probably easier for students to understand, and Bob tells me that’s called repackaging, and I sort of thought that through all my teaching I do a fair bit of repackaging, a lot of the time, so I guess that was just a trait that I use and has been pretty successful for me, I think.

Pages