REPORT
announcing the
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producer several years ago. This film involved about 200 man-hours of T V Laboratory time. T h e con clusion seems inescapable t h a t kine scope films are much less expensive t h a n conventional ones. T h e ratio of costs probably would depend greatly on factors t h a t might v a r y from one kind of film to another. Our experience indicates t h a t the cost of any film t h a t can be made in a TV studio should be less t h a n half the cost of a conventional mo tion picture, and m a y in some cases run as low as one fourth. T h e ratio could become lower as experience in recording is gained, or if video t a p e equipment is used. A 2-reel, 70 minute kine on gravi metric techniques has been pro duced at even less cost per minute of playing time t h a n the analytical balance kine. Figure 1 gives a rough breakdown of the time re quired for each step in the produc tion process. Academic Use of Kinescope Films
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24 A
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ANALYTICAL CHEMISTRY
Established 1934.
T h e advantages of using such films in teaching are easily eval uated. After showing a 45-minute kine on the analytical balance and weighing procedure during the first laboratory period, elementary ana lytical students came up to good weighing technique several periods sooner t h a n when the film was not shown. The proportion of students having to repeat balance experi ments was much lower when the kine was shown. The balance film does not teach the student perfect weighing tech nique, for his retention of w h a t he sees is incomplete. The important fact is t h a t the film gives everyone a starting point for individual in struction. As the students begin to weigh, the instructor sees only a few students doing only a few spe cific things incorrectly, and it is easy to set them straight. AVithout the film, an instructor often sees so m a n y students doing so m a n y things incorrectly t h a t he hardly knows where to begin. The showing of an unedited kine on gravimetric techniques reduced the proportion of students who ob tained poor results on the gravi metric chloride determination to less t h a n half of the proportion in previous semesters. T h e technique
