#ASEslowchat Tuesday: Practicals


I can’t comment on what is happening in my classroom, or my department. Because I don’t have a classroom; instead I work with teachers in their classrooms, supporting their departments. So most of what I’ll be sharing will be at one step removed, but it is based on what ‘real’ teachers have told me is happening in their schools. I’ve played around with the stimulus questions a little.
Which required practicals have you completed with your classes; have you only completed these, or gone beyond them? Why?

I posted a little while back about how I felt the required practicals should fit into a balanced science curriculum. (This was a different post to one from even earlier, based o a draft of the AQA required pracs.) Nothing I’ve seen has caused me to change my mind. The summary is that whether a practical is required or not it should be used in the same way; to support teaching of science content and skills. It might, of course, be worth returning to the required practicals as part of the organised review/revision schedule, because they’re effectively content. Until then, ask the same questions, practise the same skills, as you would for any practical. (And, of course, don’t neglect these aspects if a practical is ‘unrequired’!)

Has the GCSE impacted on the work of the technicians in the department? Have you had any issues with equipment?

Not being in a school full-time, I’m not sure about the workload side of this. I don’t think it’s been a huge issue – certainly compared to lots of ISAs to worry about! (I hope school technicians are being encouraged to contribute to this topic, by the way.) But I have been doing a fair bit about the physics practicals with teachers, in school and by email, so I have a few resources to point to.

There is a dedicated TalkPhysics group for the GCSE required practicals – obviously just the physics ones. It’s fairly quiet at the moment, but I/we would love to see more teachers on there swapping ideas and answers, for example about specific components for I/V graphs or precise methods for using a ripple tank. If you’re not already a member, you can get a free login in a day or so, and the group is open to all. Technicians and all teachers of physics – not just physics specialists – are welcome. Please join in.

Most equipment issues I’ve heard about have been predictable:

  • Getting a class around a ripple tank is hard. Much of the work can be done in pairs by putting a piece of laminated squared paper in a Gratnells tray – other trays are available – adding a centimetre of water with a couple of drops of ink, then making and timing ripples. Very fast, very cheap, and lots of data to criticise.
  • Dataloggers for a=F/m. As you might expect, manufacturers are trying to log complete systems which will work brilliantly for a week then be a pain to set-up and calibrate. If you can use phones in school, kids can probably use slow-motion cameras to collect some useful data. Alternatively, I’m a huge fan (no commision, sadly) of the Bee Spi V lightgate. It displays either speed or acceleration of an object passing through it. It doesn’t log it, which to my mind is an advantage as it means kids have to do the table/points/line bit themselves. They’re £20 each, run on batteries and don’t need to be plugged into any device.
  • The specific heat capacity practical – assuming you have the kit – has always produced data with, shall we say, lots to comment on. An improved method is available from PracticalPhysics, and it’s easier if you can (a) use a joulemeter and (b)record the maximum temperature, not the temperature at the end of the heating time.

How are you developing knowledge of practical work and investigations in your teaching ready for the examinations? 

‘Required Practicals’ is one of the sessions I run in schools as part of my day job with the IOP. So allow me to invite you to a virtual session, which will require you to imagine all the hands-on sections. There are presenter notes with even more links than in the slides themselves. PNCs will often run their own versions of these, and we do a lot at days and events open to all teachers. Please consider this an invitation.

If in doubt, checking out the work of Ian Abrahams is always worthwhile. He’s got a book out with Michael Reiss fairly recently: Enhancing Learning with Effective Practical Science 11-16, which I will buy as soon as my next freelance cheque arrives. Unless anyone would like me to review it, hint hint. He writes regularly in SSR so you’ve probably experienced a flavour of his work already.

A few years ago, Demo: The Movie was unleashed on an unsuspecting world by @alomshaha and co. It should be required watching for all science teachers and departments, and provides some great ideas about how to make demonstrations much better for learning. He’s got loads of films, some of which aren’t directly relevant but the techniques discussed are great. I reflected on some of the material in a blog post too.

Other resources I’d recommend (there will undoubtedly be some overlap) are collated at STEM Learning (the eLibrary that was, once upon a time). And I always like to put in a word for the SchoolPhysics materials by Keith Gibb, author of the Resourceful Physics Teacher.

Something I’ve chatted about in workshops, on Twitter and elsewhere; you may find it useful to break down the POE approach in a slightly more specific way which I call PRODMEE:

  • Predict: what do you think will happen? (encourage specific changes to specific variables)
  • Reason: why do you think that? (from other science content, other subjects, life experience)
  • Observe: what actually happens? (we may need to ensure they’re looking the right way)
  • Describe: in words, what happened? (qualitative results)
  • Measure: in numbers, what happened? (quantitative results, devices, accuracy/precision, units)
  • Explain: what’s the pattern and does it match the prediction? (digging into the mechanism)
  • Extend: why does this matter? (other contexts, consequences for everyday life)

What resources or advice can you share with other teachers about approaching a specific required practical? What issues and opportunities have you come across when going about teaching the required practicals to your classes?

A few suggestions I’ve made in workshops, often based on conversations with teachers; this is obviously an incomplete list!

  • Density is boring; why not provide a few blobs of blue-tac and have kids plot mass against volume on a graph. Make it more challenging by hiding a ball bearing inside one to provide an anomaly to the line of best-fit. Or can students separate LEGO, Mega-Bloks etc based on density?
  • Hooke’s Law: as the kids have already seen it, why not try using strawberry laces? Alternatively, there’s a simple set-up using copper wire from PracticalPhysics. And you can always use it to hammer home the idea of science-specific vocab, because ‘elastic’ bands aren’t elastic.
  • Acceleration: I mentioned Bee Spi V for measuring earlier. My only other suggestion is to always teach it as F/m=a so you start with the cause (force), shared out because of the conditions (mass) which leads to a consequence (acceleration).
  • Ripples: discussed above, but you can also use a speaker as a vibration generator for some interesting results.
  • Heat capacity: An old experiment uses lead shot which falls a known distance and heats up. Like stroking a metal lump with a hammer, this is a nice example of the idea that the energy in a thermal store can increase without ‘heating’ as we might normally consider it.
  • I/V characteristics are a lot more interesting if students must compare results from a mystery component to standard graphs. This is included in the presentation of my workshop, linked above.
  • Resistance, series and parallel: instead of just reusing the old ISA hardware, why not try taking measurements of different versions of squishy circuits dough?

 

 

 

 

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Energy Stores and Pathways

Tonight’s #asechat will involve Charles Tracy, the IoP’s Head of Education (and one of my bosses), discussing the new approach adopted by exam boards from this year. There’s lots of information at Supporting Physics Teaching, which is free to access and needs no sign-in. Other sites and resources will hopefully move over to this terminology (BBC Bitesize already has, for example). But why should we bother?

Energy is one of those topics, isn’t it? We teach it several times, but the kids seem to hang on to their misconceptions. Partly this is because it’s a word which is used in everyday life, often interchangably with power. Partly it’s the way students get mixed up with energy ‘resources’ (or as I prefer to teach it, ‘ways to make electricity’.

We shouldn’t be surprised that this causes problems. Energy is at heart a very abstract concept, and so one which is difficult for students to grasp. Does it make things happen? Well, not always – and this leads to students confusing energy with force. I used to divide the ‘types’ of energy into potential and moving categories, which I suppose could be seen as a crude version of this new approach.

In the simplest possible description, energy is about bookkeeping or currency. It turns out that when objects interact, often via forces, then we can do some maths which describe the change. What’s interesting is that if we pay attention, then the same number comes up more than once. This tells us that something is conserved.

We call that something energy and say it has been transferred from one place to another. Calling those places stores emphasizes that they still have whatever they were given. This sounds similar to past approaches but avoids the idea of distinct ‘chemical energy’ being turned into ‘electrical energy’ and so on. SPT has a good comparison.

So we teach energy concepts to make it easier to do calculations. We can’t measure energy directly, but the equations we use allow us to make measurements, which allow us to make deductions, which in turn allow us to make predictions.

That sounds a lot like science, doesn’t it?

Energy moves from one store to another via pathways. These are actions – verbs, if you like – which describe a change in a system. The IoP is suggesting using the word shift rather than transfer. (I would suggest one good reason to do so is to avoid the mix up with transform, which suggests there are different kinds of energy.) I found the diagram of possible pathways at SPT useful.

Several approaches are possible, including taking a ‘snapshot’ before and after an event, or showing the amount of energy in each store with orange liquid. There are of course others, many of which are visual and so provide an anchor for students to observed reality. This isn’t to recommend VAK of course – only to suggest that making this concept ‘stract’ can only be a good thing.

I’ll be taking part in the session this evening, and I’ll add a link to the archive afterwards. I’m sure there’ll be an advert for TalkPhysics, which is one place to get access to ongoing advice and support on this and other approaches. It may be short notice but please pass on the link for tonight’s chat; the more the merrier.

#asechat and #pimpmydemo

#asechat and #ukedchat

It happened completely by accident. I happened to be on Twitter yesterday evening and some interesting posts showed up in my timeline tagged with #asechat. So I joined in.

I already sporadically take part in #ukedchat. If you don’t, it’s worth a look; you may have recently read the Guardian article about it (which they ironically tweeted about without the hashtag). Once a week, on Thursday evenings from 8-9pm UK time a bunch of teachers discuss a topic. It gets crazy, as the 40+ page archive testifies, but it’s well worth the time. The topic is voted on during the week beforehand, then the chat is moderated by some brave soul. You miss lots of stuff – the sheer pace guarantees that – but can catch up with the weekly archive, if you want. When I can make it I come away having picked up a few good ideas and wanting to try them out. I suppose the idea is to provide the same environment as the coffee break during a TeachMeet – also a great idea.

Anyway. So this chat was the first one, a trial run specifically for science teachers and educators to share ideas. You can read the archive, if you want. The name #asechat is a convenient label, but you don’t need to be a member of the ASE to join in. (It’s worth considering, but I don’t think anyone’s planning on pressganging.) All you need to do is be prepared to listen, or even better to join in. It will be much easier if you use a twitter interface with a decent search function; for what it’s worth, I like TweetDeck. (If you don’t ‘get’ Twitter, and you’ve still read this far, check out this video.) The plan is for it to happen each Monday evening from 8-9. Maybe I’ll ‘see’ you there.

#pimpmydemo

A few weeks back I swapped a few tweets with other science teachers about the little tips and tweaks that make demonstrations better. For a while now I’ve been collecting these ideas for myself, like we all do. This has usually involved scribbling on printouts or textbooks, less often an electronic ‘cheat sheet’. I’ve used books like The Resourceful Physics Teacher (out of print I think but he’s now got a website, SchoolPhysics) and there are regular features in magazines and journals. But why, I asked, don’t we share these ideas with each other on Twitter by coming up with a useful hashtag? And so #pimpmydemo was born (probably inspired by the book I’ve seen called Pimp Your Lesson). There were a few dozen responses of colleagues who felt it would be useful, then real life got in the way. During the #asechat I raised the idea again and there was enough interest it seemed worth taking it further. Of course, as it was my idea, I couldn’t exactly pass it on to somebody else…

I’ve set up an archive through a site called TwapperKeeper. The archive URL is http://twapperkeeper.com/hashtag/pimpmydemo and it should be automatically updating from now. And to be honest, that’s about it. I’m not trying to run anything, or take credit for anyone’s ideas. I’d suggest that if you can’t explain your idea in 140 characters, including a link to a details page would be worthwhile. If it gets going – and I hope it does – I suspect we’ll see links to blogs, sites such as Getting Practical and YouTube. Perhaps people will ask for help, by using the tag, as well as offering it. We’ll just have to see if anyone except me and a couple of others are interested.

If you think it’s a good idea, all you need to do is tell your followers. This isn’t going to happen by me or you putting out a few ideas and waiting for magic to happen. But it would be interesting to see what happens if the idea spreads…