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.