Archive for the Education Category

The Crocodile Maths Challenge

Posted in Cute Problems, Education with tags , , , , on October 14, 2015 by telescoper

I’m indebted to an anonymous informant (John Peacock) for drawing my attention to a BBC Scotland story about an allegedly challenging examination question that appeared on a “Higher Maths” paper. For those of you not up with the Scottish examination system, “Highers” are taken in the penultimate year at school so are presumably roughly equivalent to the AS levels taken in England and Wales.

Anyway, here is the question that is supposed to have been so difficult. For the record, it’s Paper 2, Question 8 of the SQA examination 2015.

crocodile_questionCall me old-fashioned, but it doesn’t seem that difficult to me  but I never took Scottish Highers and there have been many changes in Mathematics education since I did my O and A-levels; here’s the O-level Mathematics paper I took in 1979, for example.  I wonder what my readers think? Comments through the box if you please.

Feel free to give it a go. If you get stuck here’s a worked solution!

An Open Letter to the Times Higher World University Rankers

Posted in Education, The Universe and Stuff with tags , , , , , , , , on October 5, 2015 by telescoper

Dear Rankers,

Having perused your latest set of league tables along with the published methodology, a couple of things puzzle me.

First, I note that you have made significant changes to your methodology for combining metrics this year. How, then, can you justify making statements such as

US continues to lose its grip as institutions in Europe up their game

when it appears that any changes could well be explained not by changes in performance, as gauged by the metrics you use,  but in the way they are combined?

I assume, as intelligent and responsible people, that you did the obvious test for this effect, i.e. to construct a parallel set of league tables, with this year’s input data but last year’s methodology, which would make it easy to isolate changes in methodology from changes in the performance indicators.  Your failure to publish such a set, to illustrate how seriously your readers should take statements such as that quoted above, must then simply have been an oversight. Had you deliberately witheld evidence of the unreliability of your conclusions you would have left yourselves open to an accusation of gross dishonesty, which I am sure would be unfair.

Happily, however, there is a very easy way to allay the fears of the global university community that the world rankings are being manipulated: all you need to do is publish a set of league tables using the 2014 methodology and the 2015 data. Any difference between this table and the one you published would then simply be an artefact and the new ranking can be ignored. I’m sure you are as anxious as anyone else to prove that the changes this year are not simply artificially-induced “churn”, and I look forward to seeing the results of this straightforward calculation published in the Times Higher as soon as possible.

Second, I notice that one of the changes to your methodology is explained thus

This year we have removed the very small number of papers (649) with more than 1,000 authors from the citations indicator.

You are presumably aware that this primarily affects papers relating to experimental particle physics, which is mostly conducted through large international collaborations (chiefly, but not exclusively, based at CERN). This change at a stroke renders such fundamental scientific breakthroughs as the discovery of the Higgs Boson completely worthless. This is a strange thing to do because this is exactly the type of research that inspires  prospective students to study physics, as well as being direct measures in themselves of the global standing of a University.

My current institution, the University of Sussex, is heavily involved in experiments at CERN. For example, Dr Iacopo Vivarelli has just been appointed coordinator of all supersymmetry searches using the ATLAS experiment on the Large Hadron Collider. This involvement demonstrates the international standing of our excellent Experimental Particle Physics group, but if evidence of supersymmetry is found at the LHC your methodology will simply ignore it. A similar fate will also befall any experiment that requires large international collaborations: searches for dark matter, dark energy, and gravitational waves to name but three, all exciting and inspiring scientific adventures that you regard as unworthy of any recognition at all but which draw students in large numbers into participating departments.

Your decision to downgrade collaborative research to zero is not only strange but also extremely dangerous, for it tells university managers that participating in world-leading collaborative research will jeopardise their rankings. How can you justify such a deliberate and premeditated attack on collaborative science? Surely it is exactly the sort of thing you should be rewarding? Physics departments not participating in such research are the ones that should be downgraded!

Your answer might be that excluding “superpapers” only damages the rankings of smaller universities because might owe a larger fraction of their total citation count to collaborative work. Well, so what if this is true? It’s not a reason for excluding them. Perhaps small universities are better anyway, especially when they emphasize small group teaching and provide opportunities for students to engage in learning that’s led by cutting-edge research. Or perhaps you have decided otherwise and have changed your methodology to confirm your prejudice…

I look forward to seeing your answers to the above questions through the comments box or elsewhere – though you have ignored my several attempts to raise these questions via social media. I also look forward to seeing you correct your error of omission by demonstrating – by the means described above – what  changes in league table positions are by your design rather than any change in performance. If it turns out that the former is the case, as I think it will, at least your own journal provides you with a platform from which you can apologize to the global academic community for wasting their time.

Yours sincerely,

Telescoper

The 9 kinds of physics seminar

Posted in Education, The Universe and Stuff on October 2, 2015 by telescoper

I just couldn’t resist reblogging this!! :-)

Many Worlds Theory

As a public service, I hereby present my findings on physics seminars in convenient graph form.  In each case, you will see the Understanding of an Audience Member (assumed to be a run-of-the-mill PhD physicist) graphed as a function of Time Elapsed during the seminar.  All talks are normalized to be of length 1 hour, although this might not be the case in reality.

Typical

The “Typical” starts innocently enough: there are a few slides introducing the topic, and the speaker will talk clearly and generally about a field of physics you’re not really familiar with.  Somewhere around the 15 minute mark, though, the wheels will come off the bus.  Without you realizing it, the speaker will have crossed an invisible threshold and you will lose the thread entirely.  Your understanding by the end of the talk will rarely ever recover past 10%.

Ideal

The “Ideal” is what physicists strive for in…

View original post 763 more words

Flexible Degrees through Sussex Choice

Posted in Education with tags , , , , , , on September 24, 2015 by telescoper

I just noticed an item in the Times Higher about a new development in the approach to degree structures at the University of Leicester. The piece begins

A growing number of students undertake several work placements and internships over the course of their degree to increase their chances of securing a graduate-level job. But an initiative at the University of Leicester aims to make it easier for undergraduates to learn the range of skills that employers are looking for during their studies.

I feel obliged to point out that, in fact, here at the University of Sussex we already have a scheme (called “Sussex Choice”) that already allows this, as well as a number of other initiatives under the same banner. The University of Leicester’s “initiative” is of course a good development, but it’s not as ground-breaking as the Times Higher story suggests.

Sussex choice allows students the following opportunities:

  • “Electives” in topics not connected with the main subject of their course, e.g. science modules for Arts and Humanities students. I teach on one of these, actually.
  • “Pathways” allowing students to transform their degree into a major/minor combination. This is basically what the University of Leicester is proposing to start.
  • “Placements”, i.e. paid internships, which can be either professional (e.g. in industry) or research-based (e.g. working with a research group inside our outside the University). These can be either integrated within the course of study, leading to (for example) a  degree title which includes (“with a Professional Placement” or “with a Research Placement”) or “voluntary”, usually in subject not directly related to the degree subject.
  • “Study Abroad” opportunities, allowing students to take a term or a year abroad at one of our partner universities.

With very few exceptions – generally due to restrictions imposed by accrediting bodies for some degree programmes – It is possible, for example,  in the Department of Physics & Astronomy, for students to do a Research Placement abroad, combining the latter two of these opportunities; two of our students went to Tsinghua University in China to do precisely this, as part of an exchange agreement. You can read about the students’ experiences of these and other opportunities at Berkeley and  Texas in the United States and Uppsala University (Sweden) here.

Here is the PVC Clare Mackie (my boss!)  explaining the Sussex Choice scheme in a little video…

How to Solve Physics Problems

Posted in Cute Problems, Education with tags , , , , , , on September 18, 2015 by telescoper

It’s Friday afternoon at the end of Induction Week here at the University of Sussex. By way of preparation for lectures proper – which start next Monday – I gave a lecture today to all the new students in Physics during which I gave some tips about how to tackle physics problems, not only in terms of how to solve them but also how to present the answer in an appropriate way.

Richard-Feynman-cornellI began with Richard Feynman’s formula (the geezer in the above picture) for solving physics problems:

  1. Write down the problem.
  2. Think very hard.
  3. Write down the answer.

That may seem either arrogant or facetious, or just a bit of a joke, but that’s really just the middle bit. Feynman’s advice on points 1 and 3 is absolutely spot on and worth repeating many times to an audience of physics students.

I’m a throwback to an older style of school education when the approach to solving unseen mathematical or scientific problems was emphasized much more than it is now. Nowadays much more detailed instructions are given in School examinations than in my day, often to the extent that students  are only required to fill in blanks in a solution that has already been mapped out.

I find that many, particularly first-year, students struggle when confronted with a problem with nothing but a blank sheet of paper to write the solution on. The biggest problem we face in physics education, in my view, is not the lack of mathematical skill or background scientific knowledge needed to perform calculations, but a lack of experience of how to set the problem up in the first place and a consequent uncertainty about, or even fear of, how to start. I call this “blank paper syndrome”.

In this context, Feynman’s advice is the key to the first step of solving a problem. When I give tips to students I usually make the first step a bit more general, however. It’s important to read the question too. The key point is to write down the information given in the question and then try to think how it might be connected to the answer. To start with, define appropriate symbols and draw relevant diagrams. Also write down what you’re expected to prove or calculate and what physics might relate that to the information given.

The middle step is more difficult and often relies on flair or the ability to engage in lateral thinking, which some people do more easily than others, but that does not mean it can’t be nurtured.  The key part is to look at what you wrote down in the first step, and then apply your little grey cells to teasing out – with the aid of your physics knowledge – things that can lead you to the answer, perhaps via some intermediate quantities not given directly in the question. This is the part where some students get stuck and what one often finds is an impenetrable jumble of mathematical symbols  swirling around randomly on the page. The process of problem solving is not always linear. Sometimes it helps to work back a little from the answer you are expected to prove before you can return to the beginning and find a way forward.

Everyone gets stuck sometimes, but you can do yourself a big favour by at least putting some words in amongst the algebra to explain what it is you were attempting to do. That way, even if you get it wrong, you can be given some credit for having an idea of what direction you were thinking of travelling.

The last of Feynman’s steps  is also important. I lost count of the coursework attempts I marked this week in which the student got almost to the end, but didn’t finish with a clear statement of the answer to the question posed and just left a formula dangling.  Perhaps it’s because the students might have forgotten what they started out trying to do, but it seems very curious to me to get so far into a solution without making absolutely sure you score the points.  IHaving done all the hard work, you should learn to savour the finale in which you write “Therefore the answer is…” or “This proves the required result”. Scripts that don’t do this are like detective stories missing the last few pages in which the name of the murderer is finally revealed.

So, putting all these together, here are the three tips I gave to my undergraduate students this morning.

  1. Read the question! Some students give solutions to problems other than that which is posed. Make sure you read the question carefully. A good habit to get into is first to translate everything given in the question into mathematical form and define any variables you need right at the outset. Also drawing a diagram helps a lot in visualizing the situation, especially helping to elucidate any relevant symmetries.
  2. Remember to explain your reasoning when doing a mathematical solution. Sometimes it is very difficult to understand what students are trying to do from the maths alone, which makes it difficult to give partial credit if they are trying to the right thing but just make, e.g., a sign error.
  3.  Finish your solution appropriately by stating the answer clearly (and, where relevant, in correct units). Do not let your solution fizzle out – make sure the marker knows you have reached the end and that you have done what was requested. In other words, finish with a flourish!

There are other tips I might add – such as checking answers by doing the numerical parts at least twice on your calculator and thinking about whether the order-of-magnitude of the answer is physically reasonable – but these are minor compared to the overall strategy.

And another thing is not to be discouraged if you find physics problems difficult. Never give up without a fight. It’s only by trying difficult things that you can improve your ability by learning from your mistakes. It’s not the job of a physics lecturer to make physics seem easy but to encourage you to believe that you can do things that are difficult.

To illustrate the advice I’ve given I used this problem, which I leave as an exercise to the reader. It is a slightly amended version the first physics problem I was set as tutorial work when I began my undergraduate studies way back in 1982. I think it illustrates very well the points I have made above, and it doesn’t require any complicated mathematics – not even calculus! See how you get on…

problem

Widening Participation in Physics

Posted in Education with tags , , , , on September 9, 2015 by telescoper

Following on from a provocative post I wrote a couple of weeks ago on this blog (which was subsequently reblogged by the Times Higher), I was contacted by Paul Crowther who sent me a copy of the slides used by Peter Main of the Institute of Physics in a talk in May 2015 on the subject of Widening Participation in Physics. With Peter Main’s permission I’m sharing those slides here as a service to the Physics community. There’s a lot of interesting information in these slides, which I think many UK physicists would be interested in.

Research Funding – A Modest Proposal

Posted in Education, Science Politics with tags , , , , , on September 9, 2015 by telescoper

This morning, the Minister for Universities, Jo Johnson, made a speech in which, among other things, he called for research funding to be made simpler. Under the current “dual funding” system, university researchers receive money through two main routes: one is the Research Excellence Framework (REF) which leads to so-called “QR” funding allocations made via the Higher Education Funding Council for England (HEFCE); and the other is through research grants which have to be applied for competitively from various sources, including the Seven Research Councils.

Part of the argument why this system needs to be simplified is the enormous expense and administrative burden of the Research Excellence Framework.  Many people have commented to me that although they hate the REF and accept that it’s ridiculously expensive and time-consuming, they didn’t see any alternative. I’ve been thinking about it and thought I’d make a suggestion. Feel free to shoot it down in flames through the box at the end, but I’ll begin with a short introduction.

Those of you old enough to remember will know that before 1992 (when the old `polytechnics’ were given the go-ahead to call themselves `universities’) the University Funding Council – the forerunner of HEFCE – allocated research funding to universities by a simple formula related to the number of undergraduate students. When the number of universities suddenly increased this was no longer sustainable, so the funding agency began a series of Research Assessment Exercises to assign research funds (now called QR funding) based on the outcome. This prevented research money going to departments that weren’t active in research, most (but not all) of which were in the ex-Polytechnics. Over the years the apparatus of research assessment has become larger, more burdensome, and incomprehensibly obsessed with short-term impact of the research. Like most bureaucracies it has lost sight of its original purpose and has now become something that exists purely for its own sake.

It is especially indefensible at this time of deep cuts to university core funding that we are being forced to waste an increasingly large fraction of our decreasing budgets on staff-time that accomplishes nothing useful except pandering to the bean counters.

My proposal is to abandon the latest manifestation of research assessment mania, i.e. the REF, and return to a simple formula, much like the pre-1992 system,  except that QR funding should be based on research student (i.e. PhD student) rather than undergraduate numbers. There’s an obvious risk of game-playing, and this idea would only stand a chance of working at all if the formula involved the number of successfully completed research degrees over a given period .

I can also see an argument  that four-year undergraduate students (e.g. MPhys or MSci students) also be included in the formula, as most of these involve a project that requires a strong research environment.

Among the advantages of this scheme are that it’s simple, easy to administer, would not spread QR funding in non-research departments, and would not waste hundreds of millions of pounds on bureaucracy that would be better spent actually doing research. It would also maintain the current “dual support” system for research, if that’s  a benefit.

I’m sure you’ll point out disadvantages through the comments box!


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