#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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3 thoughts on “#ASEslowchat Tuesday: Practicals”

  1. Nice article but..density is boring? I imagine this isn’t you speaking, but what teachers say in sessions!! Compare the density of full sweetness and diet drinks (real life situation – working in a cafe & you’ve muddled the drinks, how can you tell which is which?); compare the density of currency – the alloy changed in the past so stacks of older and newer 1p and 2p coins are different heights; use a hygrometer (from the brewing department of Wilkos) to check alcohol content of solutions …probably not good practice to use gin from home, however tempting on Friday afternoon!

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