British Kinematography (1953)

180 BRITISH KINEMATOGRAPHY Vol. 22, No. 6 and the behaviour of free moving electrons, the diagram makes an imaginative contribution of unique character. Recently, in describing the chemical processes of a blast furnace, a carefully planned series of simple diagrams enabled trainees who had had little science teaching at school and little idea of atomic theory, to grasp the essential principles involved without difficulty. Great care needs to be exercised because of two fairly obvious dangers. The first is the danger of oversimplification. A cleverly conceived diagram may convey the impression that a specific scientific phenomenon can be simply explained, whereas in fact there is more to it than appears to be the case. The other danger is that the instructional film may create the impression that an understanding of complicated scientific processes can be acquired easily and without considerable mental effort and study. This can easily and unexpectedly arise through the use of the analogy : the pupil ma\ thoroughly understand the analogy without being able to transfer his understanding to the subject. Many examples of this will spring to mind — cartoon figures to illustrate the pressure of voltage, or the varying strengths of electrical resistances, and the familiar figure of the horse and plough when discussing horse-power. Perhaps an even bigger danger is the false analogy — water flowing in a pipe to convey an understanding of the behaviour of electric current — though this is now largely a thing of the past. Having made these reservations it would onh be fair to add that the use of animated diagram and cartoon in instructional films is to-day one of the greatest means for effective teaching yet devised. Diagrams often provide that element of assistance which enables a student to grasp the basic principles of a difficult theory or process so that he is able to go forward much more successfully. It is relevant here to refer to model work which is closely allied to diagram and cartoon. Sometimes it is more effective to use models because a clearer conception of actuality is obtained. The use of models in the film The Nature of Plastics to teach the basic facts of the structure of plastics, and the model sequences in the Shell Unit film on the principles of oil refining processes by catalytic cracking plant are excellent examples of this technique. The technical questions involved in producing good diagrammatic cartoon and model work are worthy of a separate paper, but one or two guiding principles can be mentioned. Simplicity and clarity are of first importance. It is a mistake to attempt too much animation at the same time, as the eye cannot follow it. The action should be built up from first principles, step by step, until the whole process is depicted. Never be afraid of repeating the action two, or, if necessary, three times, and allow each sequence sufficient length to ensure that it is completely grasped before the next sequence begins. The rate of development or tempo of diagram sequences should invariably be quite slow and deliberate if the fullest possible teaching value is to be obtained. Pre-Production Planning More instructional films fail through inadequate pre-production planning than from any other cause. A clear definition of the subject matter and of the ultimate use of the film are of primary importance. The essential prerequisite to success is the preparation of a detailed shooting script in which every scene and every word is justified by its value to the whole. The film must have a single, well-defined purpose. Failure accompanies attempts to make a film fulfil two or three different functions for a similar number of different audiences. A great deal has already been written on effective collaboration in scripting an educational film. The film technician must work in harmony with an experienced teacher and often with a qualified subject specialist ; but effective films cannot be made by committees, and once the scope and content have been worked out and questions of technical accuracy have been settled, the film makers should have the utmost freedom in deciding all those creative and technical matters involved in translating the script into