Monthly Archives: December 2016

IoP Energy: “Store” of Wisdom or Little Shop of Horrors?

“Something with a lot of energy will kill you.”

This has stayed with me from my PGCE course at Swansea University, many years ago. It was said by Frank Banks, the course tutor, in response to the question “What’s the simplest way to describe energy?”

And as pithy descriptions of energy go, it’s not half-bad. A small stone, dropped from the top of a skyscraper: lots of energy before it hits the ground — it could kill you. A grand piano, dropped from six feet above your head: lots of energy — it could kill you. Licking your fingers and touching the bare live and neutral wires in a socket: the conduction electrons in your body suddenly acquire a lot of energy — and yes, they could kill you. (With alternating current, of course, the electrons that will kill you are already inside your body — freaky!)

This attention-grabbing definition of energy seems to lead naturally to a more formal definition of “Energy is the capacity to do work“. This still leaves the problem of defining work, of course, but as R. A. Lafferty once said, that’s another and much more unpleasant story.

As I mentioned in an earlier post, I have been writing the Energy scheme of work for GCSE Science. As part of that brief, I wrote a short summary for my science colleagues of the IoP’s new approach to energy. I present it below without much amendment (or even a proper spellcheck) in the hope that someone, somewhere, at some time — may find it useful  🙂

The problem with teaching energy

One reason for the difficulty in deciding what to say about energy at school level is that the scientific idea of energy is very abstract.  It is, for example, impossible to say in simple language what energy is, or means.  Another problem is that the word ‘energy’ has entered everyday discourse, with a meaning that is related to, but very different from, the scientific one. [ . . .]

This ‘forms of energy’ approach has, however, been the subject of much debate. One criticism is that pupils just learn a set of labels, which adds little to their understanding. For example, one current textbook uses the example of a battery powered golf buggy. It asks pupils to think of this in the following terms:

Chemical energy in the battery is transformed into electrical energy which is carried by the wires to the motor. The motor then transforms this into kinetic energy as the buggy moves.

This, however, adds nothing to the following explanation, which does not use energy ideas:

The battery supplies an electric current which makes the motor turn. This then makes the buggy move.

A good general rule when explaining anything is that you should use the smallest number of ideas needed to provide an explanation, and not introduce any that are unnecessary

Robin Millar [2012] http://www.lancsngfl.ac.uk/nationalstrategy/ks3/science/files/TeachingAboutEnergy(RobinMillar).pdf

Energy – a new hope (!)

The new approach to the teaching of energy developed by the Institute of Physics (IoP) suggests that we limit our consideration of energy to situations where we might want to do calculations (at KS4, KS5 or beyond).

We should talk of energy being stored and shifted. The emphasis should be on the start and end of the process with minimal attention being given to any intermediate stages.

Consider the following examples:

  • lifting an object. Chemical potential energy store is emptied, and gravitational potential energy store is filled (note that we are not interested in intermediate motion as it doesn’t affect the final energy store).
  • rolling an object down a slope to the bottom. Gravitational potential energy store is emptied and thermal energy stores (of slope, of pen) increased.
  • Boiling water in kettle. Chemical store (from coal/gas power station) is emptied. Thermal store of water increased, thermal store of air increased, thermal store of kettle increased.

[Examples taken from http://scientistshavesaid.blogspot.co.uk/2013/02/teaching-energy.html]

The new approach has been adopted by all UK exam boards for their new specs and is used in the AQA approved textbooks.

The following energy stores are considered: kinetic energy store, gravitational potential energy store, elastic potential energy store, thermal energy store, chemical potential energy store, nuclear energy store, vibrational energy store, electromagnetic energy store (note: the last is limited to situations involving static electric charges and static magnetic poles in magnetic fields).[NB Items in bold are those required for GCSE Combined Science.]

One major difference is that electric current and light are no longer considered as forms of energy. Rather, these are now regarded as means of transferring energy.

Rise of the Enojis

enojis

[Image from http://www.supportingphysicsteaching.net/En02PN.html]

I suggest these energy icons should be called enojis (by analogy with emojis).

Probably the biggest adjustment for most teachers will be to avoid referring to light and sound as forms of energy and to treat them as pathways for transferring energy instead.

“Energy is the new orange” and summary

More (much more!) on the IoP’s “energy as an orange liquid” model can be found at http://www.supportingphysicsteaching.net/En02TL.html and http://www.supportingphysicsteaching.net/En02PN.html.

enoji2

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Practicals Make Perfect

The physical environment provides continuous and usually unambiguous feedback to the learner who is trying to learn physical operations, but does not respond to the learning attempts for cognitive operations.

Engelmann, Siegfried; Carnine, Douglas. Theory of Instruction: Principles and Applications (Kindle Locations 1319-1320). NIFDI Press. Kindle Edition.

Into The Dustbin Of Pedagogy?

Helen Rogerson asks: “Should we bin [science] practicals?” and then answers emphatically: “No. We should get better at them.”

I wholeheartedly concur with her last statement, but must confess that I find it hard to articulate why I feel practical science is such a vital component of science education.

The research base in favour of practical science is not as clear cut as one would wish, as Helen points out in her blog.

New-kid-on-the-blog Adam Boxer has even written a series of blog posts with the provocative title “Teaching Practical Skills: Are We Wasting Our Time?“. He writes:

[T]his then raises the question of “what about the kids who are never going to see a pipette dropper again once they’ve left school?” I don’t have a great answer to that. Even though all knowledge is valuable, it comes with an opportunity cost. The time I spend inculcating knowledge of pipette droppers is time I am not spending consolidating knowledge of the conservation of matter or evolution or any other “Big Idea.” [ . . . ] But if you’ve thought about those things, and you and your department conclude that we do need to teach students how to use a balance or clamp stand or Bunsen burner, then there is no other way to do it – bring out the practical! Not because anyone told you to, but because it is the right thing for your students.

Broadly positive, yes. But am I alone in wishing for a firmer foundation on which to base the plaintive mewling of every single science department in the country, as they argue for a major (or growing) share of ever-shrinking resources?

 

The Wrong Rabbit Hole

Image result for rabbit hole

I think a more substantive case can indeed be made, but it may depend on the recognition that we, as a community of science teachers and education professionals, have gone down the wrong rabbit hole.

By that, I think that we have all drunk too deep of the “formal investigation” well, especially at KS3 and earlier. All too often, the hands-on practical aspect plays second- or even third- or fourth-fiddle to the abstract formalism of manipulating variables and the vacuous “evaluation” of data sets too small for sound statistical processing.

 

So, Which Is The Right Rabbit Hole?

The key to doing science practicals “better” is, I think, to see them as opportunities for students to get clear and unambiguous feedback about cognitive operations from the physical environment.

To build adequate communications, we design operations or routines that do what the physical operations do. The test of a routine’s adequacy is this: Can any observed outcome be totally explained in terms of the overt behaviours the learner produces? If the answer is “Yes,” the cognitive routine is designed so that adequate feedback is possible. To design the routine in this way, however, we must convert thinking into doing.

Engelmann, Siegfried; Carnine, Douglas. Theory of Instruction: Principles and Applications (Kindle Locations 1349-1352). NIFDI Press. Kindle Edition.

 

Angle of Incidence = Angle of Reflection: Take One

It’s a deceptively simple piece of science knowledge, isn’t it? Surely it’s more or less self-evident to most people…

How would you teach this? Many teachers (including me) would default to the following sequence as if on autopilot:

  1. Challenge students to identify the angle of incidence as the independent variable and the angle of reflection as the dependent variable.
  2. Explain what the “normal line” is and how all angles must be measured with reference to it.
  3. Get out the rayboxes and protractors. Students carry out the practical and record their results in a table.
  4. Students draw a graph of their results.
  5. All agree that the straight line graph produced provides definitive evidence that the angle of reflection always equals the angle of incidence, within the limits of experimental error.

 

I’m sure that practising science teachers will agree that Stage 5 is hopelessly optimistic at both KS3 and KS4 (and even at KS5, I’m sorry to say!). There will be groups who (a) cannot read a protractor; (b) have used the normal line as a reference for measuring one angle but the surface of the mirror as a reference for the other; and (c) every possible variation of the above.

The point, however, is that this procedure has not allowed clear and unambiguous feedback on a cognitive operation ( i = r) from the physical environment. In fact, in our attempt to be rigorous using the “formal-investigation-paradigm” we have diluted the feedback from the physical environment. I think that some of our current practice dilutes real-world feedback down to homeopathic levels.

Sadly, I believe that some students will be more rather than less confused after carrying out this practical.

 

Angle of Incidence = Angle of Reflection: Take Two

How might Engelmann handle this?

He suggests placing a small mirror on the wall and drawing a chalk circle on the ground as shown:

engelmannreflection

Theory of Instruction (Kindle Location 8686)

Initially, the mirror is covered. The challenge is to figure out where to stand in order to see the reflection of an object.

engelmannreflection2

Note that the verification comes after the learner has carried out the steps. This point is important. The verification is a contingency, so that the verification functions in the same way that a successful outcome functions when the learner is engaged in a physical operation, such as throwing a ball at a target. Unless the routine places emphasis on the steps that lead to the verification, the routine will be weak. [ . . . ]

If the routine is designed so the learner must take certain steps and figure out the answer before receiving verification of the answer, the routine works like a physical operation. The outcome depends on the successful performance of certain steps.

Engelmann, Siegfried; Carnine, Douglas. Theory of Instruction: Principles and Applications (Kindle Locations 8699-8709). NIFDI Press. Kindle Edition.

Do I want to abandon all science investigations? Of course not: they have their place, especially for older students at GCSE and A-level.

But I would suggest that designing practical activities in such a way that more of them use the physical environment to provide clear and unambiguous feedback on cognitive ideas is a useful maxim for science teachers.

Of course, it is easier to say than to do. But it is something I intend to work on. I hope that some of my science teaching colleagues might be persuaded to do likewise.

A ten-million year program in which your planet Earth and its people formed the matrix of an organic computer. I gather that the mice did arrange for you humans to conduct some primitively staged experiments on them just to check how much you’d really learned, to give you the odd prod in the right direction, you know the sort of thing: suddenly running down the maze the wrong way; eating the wrong bit of cheese; or suddenly dropping dead of myxomatosis.

Douglas Adams, The Hitch-Hiker’s Guide To The Galaxy, Fit the Fourth

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Songs In The Key Of Energy

​The fact narrated must correspond to something in me to be credible or intelligible. We as we read must become Greeks, Romans, Turks, priest and king, martyr and executioner, must fasten these images to some reality in our secret experience, or we shall learn nothing rightly.

–Ralph Waldo Emerson, “History”

The autumn term is always the longest term: that long drag from the wan sunlight of September to the bleak darkness of December. This is the term that tests both the mettle and the soul of a teacher. At the end of it, many of us have cause to echo the gloom of Francisco’s lines from Hamlet — “’tis bitter cold, and I am sick at heart.”

But even when it seems like it’s all over, it’s still not over. 

The heavy hand of collective-responsibility roulette has tapped me on the shoulder. It’s my turn to write the scheme of work and resources for the next term. I am to write the energy module for the new GCSE Science course. And it must be done, dusted and finished over the Christmas break. The Christmas break.

And the surprising and unexpected truth is . . . I actually think I’m going to like doing it! Yes, really.

Strange to say, I have always enjoyed writing schemes of work. To my mind, it’s a bit like fantasy teaching instead of fantasy football. I move lesson objectives and resources hither and thither where others shift premier league strikers and goalkeepers.

Some aspects of the Science curriculum are abtruse and hard to communicate. Undoubtedly, some of the things we narrate do not always correspond closely enough to something which is already in students to be either credible or intelligible to them. The images and concepts must be fastened to some reality in their “secret experience” for them to learn rightly.

And what can we do to help them? Simply this: make sure that students get as much hands-on practical work as possible. Of course, it goes without saying (I hope!) that it should go hand-in-glove with coherent and thorough explanations of the theoretical underpinnings of scientific understanding.

One without the other is not enough.

Physics: it’s remarkably similar to Maths. But there’s a point to Physics

Let us hope that our students (in the words of R. A. Lafferty) never see a bird fly by without hearing the stuff gurgling in its stomach.

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Compliance With Necessities

​But it must be remembered, that life consists not of a series of illustrious actions, or elegant enjoyments; the greater part of our time passes in compliance with necessities, in the performance of daily duties, in the removal of small inconveniences, in the procurement of petty pleasures; and we are well or ill at ease, as the main stream of life glides on smoothly, or is ruffled by small obstacles and frequent interruption.

–Samuel Johnson, A Journey To The Western Isles (1775)

Another day, another drachma. (Teachers aren’t paid enough for it to be counted in dollars.) And a new school!

Yes, notwithstanding the fact that I am generally a supine and procrastinating creature of habit, I finally decided to take a plunge and move school. For a number of reasons, the grass looked decidedly greener elsewhere. And although it’s more a cheeky little sidestep than a promotion, so far I would say that it still “feels” right.

So I am now deep into the business of establishing myself in a brand new school. It makes you realise how much we all depend on the unwritten and unspoken rules and expectations that are grist to the mill of every workplace. But these seem writ especially (but invisibly) large in schools, or so it seems to me.

So my working life now is emphatically not a series of illustrious actions, or elegant enjoyments. Rather, it is the bread and butter of teaching: turn up; do thou thy daily duties; attempt to remove or smooth over the inconveniences of life; work to establish relationships; and procure a few petty pleasures for yourself, your colleagues, and your students.

My new school has some excellent policies and procedures. And, of course, some batshit crazy ones too. Some of them make you think that the MAT it belongs to has never read the “Ofsted Mythbusters” page. On the plus side, the Science department has developed a system that makes triple marking almost work.

I have made some other changes too. Although I’ve been working long hours, I have not installed my school email on my phone or my tablet: when I am at home I intend to be at home, without the insatiable monster of work email rearing its ugly, insistent head and colonising my every waking thought — and, sometimes, even my dreams.

And so the main stream of life glides smoothly onwards. So far, at least. Long may it continue.

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