Lewis Elton
l.Elton@pcps.ucl.ac.uk
It is now nearly thirty years since I left physics for higher education pedagogy, but on a number of occasions I have been invited to return briefly to it. This is the latest such occasion, and while, each time that I return, I find that university physics education has changed, the changes seem to be in general far more due to externally imposed constraints – lack of money, fewer and less well prepared students, employers’ demands – than to much overdue changes deliberately coming from within the physics community. There may be much that is good in university physics teaching – I am actually sure that there is – but there is also much that could be much better. So, unless things have changed very recently, let me suggest some areas for possible improvement.
In 1988, Eric Mazur of Harvard came across the work of Hestenes1 on the common-sense beliefs of physics students when they first arrive at University. To his initial amazement, he found that his very able students were as inadequate in their understanding of basic concepts as Hestenes’s students at Arizona State University2. His analysis of the problem – that the key is to ask simple questions that focus on simple problems – turns out to be somewhat inadequate, and a more correct analysis had actually been carried out earlier, in both France3 and Britain4. That analysis showed that students at school were taught physics as if they had no previous knowledge of it. But of course, they had, from the moment that they first learned about time as they crawled from one end to the other of their playpens, even though they could not yet formulate s = vt. The physics which they learned was Greek physics, largely due to Aristotle, which deals with the real world and is as valid now as it was then (Aristotle was no fool); what came in with Galileo was the rarefied world of physics, which deals with abstractions and in which frictionless point masses move for ever in straight lines. A high proportion of school physics students put this world into a separate compartment in their minds from the ‘real’ world, and concluded that physics worked in the lab, but not in the real world. They were not changed in this belief by teachers who concentrated on solving more and more difficult problems, which however were always based on simplified assumptions, without ever trying to reconcile the students’ two worlds. Not so Feynman5, who had the following rubric in the first set of exercises to his famous Lectures:
‘Use the ideas outlined in this chapter, together with your own experience and imagination, in analysing the following exercises. Precise numerical results are not expected.’
So let me ask: how many first year students really understand Newton’s laws of motion, as opposed to being able to use them to solve problems? And how many do in their final year?
Next let me turn to first year practical work. How much of it is still concerned ostensibly with the verification of well-established physical principles, in three-hour sessions, assessed by write-ups in notebooks? And how much of it is designed to meet specific and declared learning objectives and is assessed in terms of them6? Laboratory work is extremely expensive7; can we be sure that the time is well spent? If yes, why is there so much less practical work in physics courses in other countries?
When Donald Bligh wrote one of his later editions of ‘What’s the Use of Lectures?’8, he concluded that the only teaching method that was more effective than lecturing for conveying information and increase understanding was individualised instruction. I introduced it in Britain in 1971 through what was called the Keller plan9. Is anyone still practising it? And how much tutorial teaching is still predominantly tutor talk?
This is not to deny that there are and always have been good lectures, good tutorials and good practicals. Current good practice in the 1970s was studied by a group of physics educators, under the able leadership of Jon Ogborn, in four fields of physics education10 – Individual study, Tutorial teaching, Laboratory teaching, Motivation. How many university physics teachers have read the resulting books and/or have them on their shelves? If not, is that because they have not been found useful or because they have been superseded or because they have been forgotten? However, throughout all of the four books there is no suggestion that teachers – including experienced teachers – could benefit from appropriate pedagogical training. Is that still the view of at least the majority of university physics teachers?
So far, my observations have referred to the traditional teaching of the subject. But criticisms do come from employers in terms of the lack of relevant acquisition of skills, quoting – in descending order of importance – Business awareness, Communication skills, Leadership, Ability to work in a team and Problem solving11. Now one might well argue that there is no reason why a university physics education should raise the level of business awareness, but the same can surely not be said – quite independently of employers’ demands – about the others.
Enough carping and let’s become positive: there may be a way forward through a curricular movement, which started in medicine in the 1960s and is now spreading to other subjects. It is called Problem Based Learning (PBL)12, not to be confused with the traditional use of problem solving, where problems are used to illustrate previously learned theory or – in the admittedly very popular project work – to develop research skills. In PBL, the curriculum is turned back to front and a course consists of a carefully constructed set of problems which students solve in groups in a structured way. They are not however provided in advance with the knowledge required to tackle the problems; it is up to the groups, as part of their task, to identify this knowledge. Of course, this is not just any old set of problems; the sequence of problems is carefully constructed, so that the students are taken through the curriculum of the discipline. What is new is that knowledge is now linked to problems that need that knowledge and not to the logical structure of the discipline. This works in medicine, where problems arise from real situations, and linking knowledge to problems results in knowledge being seen as relevant and therefore learnt more readily. In addition, the development of diagnostic skills, which is an important aspect of problem solving in medicine, is clearly more effective when knowledge is linked to problems than when it is linked to basic disciplines. What we do not know is whether this approach could be appropriate for so highly structured a discipline as physics. But what may well transfer readily to physics is that PBL is carried out by students in groups and so the students develop group skills, which is something that employers want, quite apart from the fact that getting on better with one’s fellows (I follow here the convention of the Royal Society, which calls both women and men ‘Fellows’) seems a good idea.
In physics, we normally construct our problems so as to illustrate principles. Would it be possible to base a physics course on the solution of real problems, arising in the practice of physics? Would it even be sensible to try, when one of the glories of physics is its ability to reduce phenomena to abstract principles? A complete change to PBL might well be inappropriate for physics, but could there not be islands in the curriculum where physics could be learned from practical problems? Would the way that Feynman asked for even the simplest of his problems to be addressed, perhaps provide an entry to such an island?
I think this is where I will leave my readers. But if they want to get in touch with me about any aspect of this article, via l.elton@pcps.ucl.ac.uk, I will be delighted. And if I have put the cat among the pigeons, I am not sorry. Academic discourse thrives on dissent.
References
1 D. Hestenes (1985), ‘The initial knowledge state of College physics students’, Am. J. Phys. 53, 1043 – 1065.
2 E. Mazur (1996), ‘Qualitative vs. quantitative thinking: are we doing the right thing?’ International Newsletter on Physics Education 32 (April), 1.
3 L. Viennot (1978), ‘Le raisonnement spontané en dynamique élémentaire’, Thesis, University of Paris VII.
4 R. Driver and J. Easley (1978), ‘Pupils and paradigms: a review of literature related to concept development in adolescent science students’, Studies in Science Education 5, 61 – 84;
J. K. Gilbert and R.J. Osborne (1980), ‘I understand it, but I don’t get it: some problems of learning science’, School Science Review 61, 664 – 674.
5 R. P. Feynman et al.( 1963), ‘The Feynman Lectures in Physics, Addison Wesley.
6 D.J. Boud (1973) ,‘The laboratory aims questionnaire – a new method for course improvement?’ Higher Education 2, 81;
S. M. Kay, S. O’Connell and P. Cryer, (1981) ‘Higher level aims in a physics laboratory; a first year course at Royal Holloway College’, Studies in Higher Education 6, 177 – 184.
7 L. Elton, (1982) ‘Cost-effectiveness in laboratory teaching’, in G. Squires (ed), ‘Innovation through recession’, Society for Research into Higher Education, 100 – 107.
8 D. Bligh (1998) ‘What’s the Use of Lectures’, 5th edition, Exeter: Intellect.
9 L. Elton (1975), ‘Innovations in undergraduate physics teaching – which and why?’, Physics Education 10, 144 – 147.
10 J. Ogborn (ed) (1977), ‘Higher Education Learning Project (Physics)’, Heinemann Educational Books.
11 M. Carney (1996),’Network Survey of Physics Departments’, private communication.
12 D. Boud and G. Feletti (1991), ‘The Challenge of Problem Based Learning’, Kogan Page.
This article first appeared on the LTSN Physical Sciences website.