Expert Insights

I find that some students pick up what the mole concept is from the idea of grouping numbers of things that are every day size. 

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.

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.

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.

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.

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.

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 think to get the students to straight away mark for somebody else what they’ve just done and then to mark or take part in the marking of two other versions of the same thing is really powerful.  So it’s not so much me directly finding out what they do and don’t understand but using methods by which they can diagnose for themselves.  I haven’t got this, she has, or yep I have got most of that, she hasn’t, and I can see where she went wrong.  Very powerful, very powerful indeed. 

So you shouldn’t be rigid, you shouldn’t be rigid in what you’re going to do.  It’s always stunned me that people say you should know where you start a lecture and where you’re going to finish, and if you get to that point and you finish ten minutes early you then should just finish.  I’ve never worked on that principle.  I never know where I’m going to start because I never know where I’m going to finish, right.  So where I finished the lecture before is where I start the next day, I haven’t got a set content.  If a student asks me an interesting question and I get the feeling that they want to know that answer I’ll go off for five or ten minutes or three or four minutes answering it, and if I don’t get to the end of where I thought I was going to get to, too bad I’ll do it next time.  So you go with the flow, you don’t go with a rigid thing ‘I’ve got to get through these 15 slides today and if I don’t the world will end,’ because it won’t.

Students should [only] be limited by students' curiosity.

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