Program Branching by Use of a Carousel Projector We have found branched programs to be much more versatile learning aids than the more common linear types of programmed instruction. However, program brrtnching is s. cumbersome procedure with printed materials and most "teaching machines" designed for such techniques are quite expensive. Our programs are produced by typing each frame in a 3 X 4 in. format on a white card, using Letter Gothic type and a carbon ribbon. The cards are photographed on orthographic film to produce a whiteon-black negative. This image is then "burned" onto a diazo film to produce a white-on-blue 35 mm slide. Eachfreme costs $0.25. The complete set of slides is mounted in a. carousel tray for a 35 mm slide projector.1 Students may progress a t their own rates, reviewing or omitting sections as determined by their performance on periodic "test" slides. Each review leads to new test questions. If the student reaches an impasse, a slide directs him to seek further help from an instructor. This technique is inexpensive, easy to revise, and effective with students of varying backgrounds and learningrates. Appreciation is expressed to the Department of Chemistry, the University of Arizona for financial support and to Miss Becky Potter for evaluetion study of the project. ' Ideally, the best projection system for this program is the 35 mm Random-Access Kodak Carousel Projector, Model RA-950, from Eastman Kodak Co., 343 State Street, Rochester, N. Y. 14650. Alternatively, a standard carousel projector can be used by depressing the "select" button to permit free rotation of the carousel tray for nonlinear projection. Ron O'CONNOR O F ARIZONA UNIVERSITY TUCSON.ARIZONA 85721
138 / Journal o f Chemiml Education
