2008-10-27

Metric Tomatoes, Luddites and Lord Kelvin.

Modern students, even those who have chosen to study advanced physics, cannot understand the full imperial system, and certainly are not able to calculate using them. This is occasionally demonstrated in class when a student complains that they can't relate to the metric SI units, and goes on to immediately demonstrate that they have no idea of how many ounces there are to the pound, or stones to the ton, or inches to the yard, or yards to the mile. They are certainly unaware of the coherent imperial unit of mass, the slug or the meaning of the fathom, acre or gallon, the chain, troy-ounce or nautical mile.

I strongly suspect that this is also the case with metric martyr Janet Devers, in the papers again for heroicly refusing to display metric units alongside the imperial ones, and bravely weighing out vegetables with pound only scales. Janet is launching an appeal against her conviction, which resulted in a £5000 fine and a conditional discharge. The Magistrate said
"We note that you said you were doing this in the interests of your customers, although you ought to have known you were breaking the law in doing so."
Indeed. Janet complained that a criminal record meant she would not be able to travel to the United States to see family. Poor thing.

Everyone under the age of 45 years has studied metric units exclusively in school, since the UK went metric in 1972, sixty-eight years after Lord Kelvin collected eight million signatures calling for the adoption of metric measures. That was a fifth of the population at that time.

Hansard records Lord Belhaven and Stenton, moving the second reading of the Weights and Measures (Metric System) Bill in 1904 as saying:
The metric system has been taught in the elementary schools under the Educational Code of 1900, but it is to be regretted that though the teachers give much time and trouble to teaching this new subject, in many cases the examiners have not asked any questions in that section of arithmetic. Therefore school teachers are very much disheartened when they find that inspectors seem to look upon it in a half-hearted way and they get no credit for the time they devote to the teaching of it. If this Bill passes it will be the means of infusing a great deal more energy into this particular subject.
and continues with
The second objection to our present system is the waste of time in teaching it to children. It is not alone the teaching of the tables which I have just referred to—it is the whole system of compound addition, subtraction, multiplication, and division, and the system of computation called "Practice."

It is estimated, on high educational authority, that every child wastes one year of its arithmetical school time in learning these subjects and that in many cases the time lost is much greater. Last year inquiries were made of headmasters of schools on this subject, and 197 sent replies, of which 161 said that saving of time in teaching the metric system would be one year, thirty said it would be two years, and six that it would be three years. This gives a French or German child a great advantage over an English child, as the time saved can be applied to some more useful subject.

I should like to quote from one of the many letters received. The senior mathematical master of Edinburgh High School wrote— An average scholar would save at least a year and a half, probably two. This saving is great in itself, but if it be considered how much he saves by not being subjected to a wearisome process of acquiring the knowledge, say, to convert ordinary yards to poles and vice versâ, or square yards to perches and give a rational remainder, and the wearing out of his nervous system—not to speak of the teachers'—I conceive it to be not only a saving of time but an economy of mental effort which is incalculable. The objection does not lie only in the time which is wasted. The child is wearied and disheartened by the difficulties of the subject; and, in the case of boys at our public schools, many get such a distaste for arithmetic that they lose all desire to study mathematics afterwards, and I think this has much to do with the low standard of mathematical knowledge in this country.
Modern students, even those who have chosen to study advanced physics, cannot understand the full imperial system, and certainly are not able to calculate using them.

The Physicist, Mathematician and Engineer Lord Kelvin supported the Bill in 1904, noting in passing that the Metric system was a English invention:
While we are grateful to France for having given us the metric system, while we see France, Germany, Italy, and Austria rejoicing in the use of it, and benefiting every day by the use of it, it is somewhat interesting to know that, after all, the decimal system, worked out by the French philosophers, originated in England In a letter dated 14th November, 1783, James Watt laid down a plan which was in all respects the system adopted by the French philosophers seven years later, which the French Government suggested to the King of England as a system that might be adopted by international agreement. James Watt's objects were to secure uniformity and to establish a mode of division which should be convenient as long as decimal arithmetic lasted.
A hundred years ago, elementary schools in England started to teach metric units, while the Germans changed over completely in two weeks without obvious difficulty.

A century later, the Luddites seem to be winning.

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2008-10-15

SATs for 14-Year-Olds Scrapped

Ed Balls has finally bowed to the inevitable, accepting that the English examination system is far too bloated and there are not enough markers to process national exams for all 7, 11, 14, 15, 16-year-olds in the country. The disastrous management of last year's Key Stage 3 National Curriculum Tests (the age 14 SATs) has forced Balls to cancel them permanently. It is a shame that he did not do this for educational reasons (for example, see this previous post), but the move will still be welcomed by parents and teachers.

The main problem, though, of these national tests has always been their narrowness. They only test a predictable subset of the National Curriculum, with a question style that does not vary, making them susceptible to coaching, or teaching to the test.

However, the huge pressure on teachers to teach to the test, bleated about routinely by the unions and criticised in report after report, could be eased by two simple measures:

  • First, the General Teaching Councils could declare that teaching to the test was unprofessional. Teachers will then be free to do the right thing and stop pressurising the pupils.

  • Secondly, the Qualifications and Curriculum Authority should both take control of the copyright of the past test questions, banning their unauthorised reproduction and use in classrooms, and change the style of questions each year.

Without an obvious test to teach to, and no reliable past questions, the pressure will be on to teach the whole curriculum - exactly what was originally intended when the National Curriculum was introduced.

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2008-10-13

Biologists Shouldn't Teach Physics

Essential, foundational ideas of physics are being presented to children by teachers who know nothing about them themselves. Able children are being undermined by the belief that there is nothing in the compulsory science curriculum that cannot be taught by any science teacher and that physics teachers, bringing only enthusiasm to an inherently dull subject, are therefore not required for physics lessons.

Having just finished a unit on forces and motion with 16- and 17-year-olds, we started on work and energy. After some introductory discussions and activities, the students were given a task to research and describe how wind turbines worked, in preparation for a study of the work done by the wind. Prompted to describe how the wind makes the generator turn, each student wrote that the wind's energy did it. When pressed, one offered that the wind's kinetic energy spun the blades and the blades' kinetic energy was turned into electricity. How does kinetic energy do that then? Well, the generator turns kinetic into electricity, they said, something to do with magnets.

Well, that's just dandy, as it is really no more than a plausible sounding 'just so' story. Without the technical terms the explanation is empty. "The wind turbine has something about it that makes electricity from wind" has nothing of substance and only a patina of education. The answers are routinely consistent with the idea that energy is a sort of fluid with some physical reality, akin to the caloric whose existence was disproved when Joule showed that heat was a method of energy transfer.

So how do bright pupils routinely get through secondary school physics lessons without a working understanding of the relationship between work and energy?

The short answer is: biology teachers.

Well, not their existence per se, but their willingness to teach physics topics about which they know nothing. That, and the connivance of school managers and government ministers who pretend that every biologist, chemist, environmental scientist, biochemist, physicist, engineer, geologist, metallurgist and zoologist can be treated as a generic science teacher, and should be able to teach any science specialism to any class up to age sixteen.

Of course, that is a self-serving cynical delusion. Cynical, because having that belief allows a head teacher to claim that their school has no vacancies, even when, as is the case with at least one school that feeds to my sixth form, they have had no physics teacher for several years. That school even takes the brightest pupils and teaches them more than the minimalist physics in the 'double science' GCSE, dragging them through separate biology, chemistry and physics courses without even bothering to employ a specialist physics teacher.

But does it matter? Can't a graduate scientist teach any of the simple topics that appear in the secondary curriculum, as long as they refrain from teaching A levels?

The response must be a clear 'no'. It should be shouted from the rooftops and at all education ministers, head teachers and science department heads. Specialist science teachers are not interchangeable. Biologists, especially, do not understand physics. They are often required to teach Newton’s Laws of Motion and Energy to the younger secondary pupils, but I have yet to meet a biology teacher who understands them even in the shallowest terms.

Asked about his willingness to teach from a position of ignorance, a biologist Head of Science shrugged it off with a “Well, that’s physics”, while more recently qualified teachers say they think that they teach physics better than the specialists as their difficulties with it themselves puts them closer to the children’s’ experiences. Honestly! I have heard both comments several times.

Secondary schools in inner-city areas, schools without sixth-forms and those whose managers insist on making physics teachers teach biology and the biology teachers physics, will continue to lose physics teachers, and pupils will fail to see the wonder and coherence of physics.

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2008-10-04

Patten versus Denham

Universities Minister John Denham has heaped criticism on Chris Patten after his speech at the Headmasters' and Headmistresses' Conference last week, for suggesting that universities could not “make up for the deficiencies of secondary education”:
It is my belief that there is now widespread acceptance across our universities that the current system does not yet capture all the talent that exists in young people across the country, which is why it is all the more disappointing to hear the comments of critics like Chris Patten who have an outmoded view of the central issues in widening participation.
For Denham, "widening participation" seems to be the sole function of elite institutions. He cannot, being a good Marxist, bear the idea that Oxford will not admit the badly educated. Chris Patten, one-time Education Minister and current Chancellor of Oxford and Newcastle Universities, had complained that:
However hard we try to widen participation at Oxbridge, and I am sure you could say the same at many other universities, there is no chance whatsoever of meeting the socio-economic targets set by agents of government so long as the proportion of students getting A grades in traditional academic A-level subjects at private and maintained schools stays the same. It is as simple as that.
It is as simple as that.

As I wrote in a previous post, poorly qualified students do not do well at university. Trying to identify some degree of intrinsic worth or talent in a student at school and then transplanting them to a Russel Group university will not work: an undeveloped talent is not a sufficient preparation for advanced study. A clutch of grade As at A level is not a guarantee either, but like it or not, if a student cannot get high grades at school, for whatever reason, they will start university a long way behind their classmates.

Can universities be expected to make up in three or four years the educational scars left by thirteen years in an inner-city sink school? Denham thinks so, saying that "Education is the most powerful tool we have in achieving social justice." If he means that accepting weak candidates onto challenging courses is an indicator that social justice has been achieved, then he is seriously deluded. It is not just to set up these poor people for such a fall, as fall they will.

Social justice should not be treated as simply another high-stakes key target that can be improved by crudely manipulating the indicator variable (percentage of sink estate kids at Oxford) directly by coercing universities. The indicator is only useful if it improves indirectly, as a result of better schooling, and that will need a whole slew of 'indicators' to be manipulated: financial poverty of families; poverty of ambition in much of the working-class culture; the flight of good teachers to 'good' schools; the lack of specialist teachers; and many others.

Of course, this is a difficult task. So difficult that no country has ever solved the problem. Bashing 'posh' universities in the press is much easier.

To give the government some credit, though, Denham was making his comments about Lord Patten at a conference for the AimHigher project, which is a major scheme to tackle poverty of ambition by supporting and encouraging children who come from families with no history of Higher Education to consider university and professional careers. My own college has received money to pay for such a scheme from this project and is currently identifying and briefing suitable students and their parents.

I know this, not because of the high quality of internal staff communication, but because several students disappeared from my classroom suddenly, missing two hours of their physics lesson. Apparently, they had been instructed to skip their lessons to attend the compulsory AimHigher meeting.

Hasn't anyone learned?

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