ABSTRACT
When I was a student at the beginning of the Second World War doing a physics course I know that I must have attended lectures on atomic physics., on quantum theory, on electricity and magnetism and on other topics, and I know that some of the lecturers were very distinguished, but I find it very difficult to recall very much about them. On the other hand the lectures on sound (by D r Alexander Wood) and on physical optics (by Sir Lawrence Bragg) remain as clearly in my mind as if they were given yesterday rather than almost fifty years ago. The reason is not hard to find; they were illustrated by the most superb lecture demonstrations. I am sure that it was through my good fortune in being able to attend these superb examples of the art that I started to use lecture demonstration as one of my main techniques when my career in university teaching began. I suppose I must confess to a certain prejudice in favour of lecture demon stration but, even allowing for that, it seems to me that the evidence for the effectiveness of demonstrations as an information-transfer technique is overwhelming. Sir Lawrence Bragg1 in referring to the Christmas Lectures to young people and the
.. .superiority, as judged by the effect on the audience, of a series of experiments and demonstrations explained by a talk over a lecture illustrated by slides
says It is surprising how often people in all walks of life own that their interest in science was first aroused by attending one of
these courses when they were youngs and in recalling their impressions they almost invariably say not ‘we were told’ but ‘we were shown? this or that.
