Expert Insights

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.

Too often I think students and others think that analytical chemistry is just that measurement step.  When you use the AA, when you use the ... and doesn’t take into account, well all of the other stuff, what’s the actual problem you’re trying to solve?  What are you actually trying to do, sampling, measurement, validating your results? Because only then when you’ve got a result, only then does it actually become information.

And it’s taken me a long time to discover what sort of teacher I actually am.... I had a colleague who said to me, ‘oh you’re a narrative teacher’.  I said, ‘I’m a what’? ..... I tell stories, essentially.  I tell stories.  I turn everything into a story in some way... and again, analytical chemistry lends itself to that.  That you can link it to stories that are in the media, personal experiences, my own personal research experience.  The student’s own experience.  So it’s shared.  So while I thought I was a straight forward didactic teacher, you know I just stood there but I’m not, I asked students, ‘alright who’s got experience of this’, and then I use a narrative form to get that across, and it seems to work.

I changed my method of teaching to be a team-based learning approach where in fact as teams they are responsible to each other within the team for their level of engagement or for what they put into that team and if they don’t put in what the team thinks is useful then they get marked on that, their peers mark them on how much they’re contributing to the team’s goals.  So rather than me as the educator saying you need to do this and you need to do that, in fact the system is such that as a team they’re responsible for a certain outcome and the team must achieve that outcome and so they need to work together.  For the students who don’t put in as much as the team expects of them then there is peer pressure to increase their level of input and their engagement and if the students don’t then the team members get a chance to reflect upon that and give them a sort of team work score.

And it’s so essential, if you are in the middle of a discipline, to have a really well developed sense of what your colleagues around you are teaching, so that you can make connections.

Students see equations and panic. Students struggle to transfer mathematical knowledge to chemical situations. Students silo knowledge and find it hard to relate concepts to actual systems.

I think what I try to get students to see is that we use models and you use a model, while it works. Then when it doesn’t work you develop a more sophisticated model, and what we’re doing now is developing a more sophisticated model of the structure of the atom, of bonding between atoms. So they find that difficult, the fact that you’re putting aside the model you used previously and developing a more sophisticated one. I think that’s something, it just knocks their confidence a bit. I think we’ve got to convince them that, actually, what your teachers told you at school wasn't wrong, it’s just that this is more sophisticated, that science is all about building models to explain reality.

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.

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 know it's hard for them to 'suspend reality' and just accept a concept. They grasp for real life examples or metaphors which make sense to them. Students don't like the concept of something that can shift/change. They like one answer which is set and that's it, right or wrong - not 'shifts to the left/right'.

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