One I Made Earlier

I had an old webcam. I had time on my hands. And I had an idea.

This was never going to end well.

I’m actually pretty pleased with the result. It’s nowhere near as pretty as the one on Instructables produced by Glen Gilchrist (aka @mrgpg) but it didn’t need any power tools. Which were in the shed, and it was raining.

Start with an old webcam and a cheap lamp, in this case one from Ikea. It’s the sort of thing you might have, just make sure it has a long neck  which holds the head steady. It will need to support a bit of extra mass. (Not weight. Well, yes, weight. Anyway.)

 

DSC_0049

I used Lego, Sugru and cable ties to hold everything together. This has the advantage of being reversible, as well as quick. How you link the two parts depends on the exact models, but Lego means angles can be fixed and changed to suit your purpose. Plus, you know, Lego.

Sugru feels like blue-tack but dries within 24 hours to a firm silicone rubber. I’ve used it for outdoors repairs, making cufflinks (again with Lego, as it happens) and repairing odds and ends from cables to memory sticks. They don’t sponsor me. (Although if they want to send me some free samples…)

It works fine on my laptop, but I’ll need to try installing the drivers on a memory stick to make it properly portable. The plan is to demonstrate this in my new job and try it out myself, without the cost (100UKP+) involved in the decent models. I’ve read about uses (for example these for primary science from @dannynic) but never had the chance to put them into practice.

My first thoughts:

  • use student work immediately for “good because” and “even better if”
  • turn a small-scale practical into a class demonstration
  • have a student commentate on an experiment in progress
  • show hands-on methods like measurements and graph drawing in a realistic way

Not particularly exciting, I know, but I’m expecting to do a lot of improvisation in the new job. I’m currently putting together boxes of demonstrations, quick practicals, tips and tricks for the teachers I’ll be working with. (Post about this coming soonish.) But for now I’d love to have comments giving me better suggestions for how to use my Blue Peter Sugrued visualizer.

Demonstration or Class Practical?

It’s always a tricky one, isn’t it? Do we show them the experiment, knowing that a half-dozen or so will be messing around at the back or comparing nail varnish with their friends? Or do we let them loose with glassware and clamp stands, waiting for the crashing noises or the blank looks to begin?

Okay, I’m exaggerating. A bit. But for most of us, it’s probably taking a bit of time to think about the kinds of practicals we do, and why. Are we focused enough on what the students will learn from it? Or are we doing a particular practical or demonstration because it’s in the scheme of work, or because we’ve always done it?

I’ve used among other sources David Sang and Alom Shaha’s workshop at the ASE Conference and materials from Getting Practical and SCORE Education to produce a checklist (downloadable below, simply click on the image). The focus is about the benefits of a demonstration or a class practical. It’s an easy way to think about what can be added to an activity, or ways to tweak it to improve outcomes. Simply sharing with the students what they might be trying to gain from a practical is worthwhile – although in some cases as a plenary to avoid spoiling a surprise or insight. Simply take a moment to read through the lists, and see if you can justify the activity in terms of learning. If you’re not sure, what could you change?

There’s loads of good ideas online – the National Stem Centre eLibrary is of course one place to look – and it’s often possible to convert a practical into a demo or vice versa. For example, I demonstrate heat transfer in fluids using the two chimneys apparatus and a convection square, plus hot and cold water with food colouring in gas jars, which I first saw in ‘Nina and the Neurons’. By the third demo the kids can predict and ex0plain what’s going to happen quite well. I then give them coloured ice cubes to float in water, and to predict, explain, describe and explain again (PEOE) what they see. Bonus points for a commentary that uses key ideas such as ‘density change’.

I hope this kind of reminder is useful, for experienced teachers as well as those more recently joining the profession. Feedback would be very much appreciated, as this is my 100th post and I’ve had less than 1 comment for each on average…

 

Demonstrations (#aseconf 2/3)

I managed to make it to the 2012 ASE Conference for just one day, the Saturday. My plan is to blog it in three chunks for the sessions I attended, in order. We’ll see how it goes. These will be edited versions of my Evernote summaries of the sessions and my commentary (in italics), although I’ll link to other resources I’ve since found that I think are relevant. Apologies if I mix up any names or misquote any of the people involved. I really enjoyed the sessions and the social side, but will cover this in more detail in the third post.

Presented by David Sang (among many other roles, editor of the Practical Physics site) and Alom Shaha (teacher, film producer etc)

In an electricity and magnetism public lecture, Oersted noticed compass movement during public demo – real public science.

I’m now thinking about reenacting this for the students, perhaps as a plenary after more ‘interactive’ work.

  • Use webcam to make it visible.
  • Mark north/south without magnet, make sure kids see change, note alteration.
  • Show range of effect, compare strength of wire and earth magnetic fields.
  • Equal strength when at 45degrees.

A demo has many possible purposes, but should always – like everything we do in a lab or classroom – lead to a better understanding of some of the ideas. It can be used as a stimulus for them to do investigative work. While explaining the demo, we can give differentiated possibilities. A useful mantra should be ‘hands-on, minds-on’.

For any demonstration, there are some things to consider:

  1. Visibility/clarity
  2. Preparation and practice, e.g. clamps and where you stand
  3. Prepare for failure, be ready with explanations
  4. Ensure kids focus on important aspects – what are we changing, what is happening
  5. Involve students in practical (holding equipment, readings, recording data)
  6. Contextualise (history, application, consequences, possibilities for the future)
  7. Predict, (explain), observe, explain. (I already used this myself but now I’ve added a prompt poster to my wall)
  8. Q&A are a standard way to check ‘takeaway’ understanding (why not ask students to ask their classmates a question?)
  9. Extend (possibly via Q&A)
  10. Give correct explanation, try not to give misconceptions (although this doesn’t mean you shouldn’t use appropriate levels of model)
  11. Good opportunity to repeat the demo, perhaps with more involvement or explanation from students (giving commentary?)
  12. Summarise (giving a summary as part of a L2L split plenary would work well)
  13. Safety – nobody died.

For this one in particular (link between magnetism and electricity) can show same principle with generators, generator handles, cheap wind up torches. A wind up torch vs cell/switch/bulb would nicely demonstrate different energy changes (classic misconception is that closing switch is KE) in energy circus.

Why not do demos?

  • Safety (rarely for most – see guidance e.g. CLEAPPS)
  • Unreliable
  • Technician time/materials cost
  • Prefer to ‘learn by doing’? (NB see evidence for/against this)

All worth considering, but use them as prompts to improve quality rather than going straight for a video.

Why do as class practical?

  • Small groups can be fun/hands on
  • Practical skills
  • Know/appreciate problems eg ‘messy data’
  • Make (and justify) plans
  • Experience non daytoday phenomena

Best reason to do demo (from Alom)

We can promote ‘awe and wonder’ by showing them something they could not have observed (or perhaps appreciated in isolation) – this is worthwhile. (eg induction with lenz law in copper tube – sleight of hand helps!). This will often involve an unexpected result, perhaps because we set up the situation with an unnoticed or unappreciated ‘tweak’ or ‘cheat’.

Alom: Nobody goes into science because the science was like ‘magic’ – but because they wanted to figure out magic. Emotional engagement is a good thing, and kids link enjoyment to both teacher and subject. This improves performance, recruitment and retention.

My plan is to turn the choices – reasons to use a demonstration vs a class practical – into a checklist or flowchart for a later blog post. If you’ve any particular ideas, I’d love to incorporate them so why not comment below?

Further reading