teaching
W. ROBERT BARNARD The Ohio State University Colvmbv~Ohio WITH
ROD O'CONNOR The University of Arizona Tucson, Arizona
Television for the Modern Chemistry Classroom, Part 111 New projects; Future developments
Lectures by Color Broadcast Television at the University of Arizona
Two of the most common objections t o televised lectures in chemistry are the lack of color and the impersonal character of television teaching as opposed t o live lectures.' The University of Arizona began in September of 1968 a program of broadcast color television for its freshman chemistry majors course. Students receive the videotaped program on color receivers in viewing rooms on campus or on receivers in their homes or campus living areas. Two instructional lectures are presented each week, and several "Frontiers" lectures throughout the semester present modern applications and recent advances in chemistry. I n order to improve the student/professor contact in the course, the professor in charge teaches all the weekly discussion sections in groups of 200-250 students. Students needing or desiring more personalized attention may obtain it through a Professor-Tutorial System, in which twenty regular members of the chemistry faculty provide 2 hr/wk each for office consultat'ton with individual students. Since experience has shown that conventional lectures are generally more poorly received by television than in live classes, the televised lectures concentrate on presentation of conceptual material by audiovisual and special effects techniques. These presentations are professional broadcast quality and several utilize special television effects (see Fig. 1) that would he impossible to duplicate in a live lecture situation. Problem solving is part,icularly difficult to teach (as opposed to "to present examples of") by television. Whereas questions on conceptual material are more often generated after the student has had time t o study and think about the concept, questions on problem solving most frequently arise spontaneously during the lecture discussion of the problems. The University of Arizona program has, therefore, been designed to present some examples of problem situ:~tions by television and through assigned readings, but to reserve teaching of problem solving- for the weekly Part I of thin series, J . CHI:M.F ~ u c . ,45, 617 (1968). *In addition to teache~.-plmd~~ced films, the students may select slry of a large variety of professional super-8 films from 1
Ealine Coruoration,. Enevclouaedix B~.ittmica.Ikrper and Row, . etc. P a r t 11of this series, J.CHIIM. EDUC.,4 5 , 6 4 1 (1968).
discussion sections where the live groul) int,erraction encourages questions and comments as they arc generated ill t,he mitids of the students. Ry allowing t,he professor ill charge of the course to teach all the discussion sect,iolls, this progrtim assures all students of equivalent instruction and, a t the same time, builds a more personalized relation with the television instructor. The latter feat,ure is an important factor in improving the students' acceptance of and attent,ion to the televised lectures. As an added feature t,o the freshman course, an Smm film room is available t o the students 40 hr/wk for use of roncept and laboratory t,erhnique films. The eight,een-station room contains projection equipment for Smm and super S films, both silent and sound.% Here the student may study or review short (%I0 minute) films on topics covered in televised lectures or on terhniques to be used in the laboratory, where he will also, receive filmed i~~structions. Initial response to the new freshman program a t the University of Arizona is enthusiastic. It would appear that the combination of color television "special-
Figure 1. Prafesrional broadcast equipment such or the special cffedr the capability to rvperimpare two television imager. generator Here one. television camera hor been focused on the instructor stonding in front of o neutral background, and another camera hor a doseup view of the lattice model. .The instructor can " w d k into" o crystal lattice and out the oo3itions of the atoms and their describe the rtructwe ~~-~ bv ~ointino , coordinates. ~~
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Figure 2. Boric elements in the TV control ore switching and modulating equipment (Dynoir Electronicr), film choin with rn~gnetic-opticalround (GratlexSylvonia), 1 -in. video tope remrderr (Sony), telephone system (Automatic Electric], and coaxial cable CCTV fittings (Blonder-Tongue).
effects" lectures, live weekly discussions with the television instructor, and availability of regular faculty through the Professor-Tutorial System may prove of significant value in the teaching of freshman chemistry to large numbers of students. Prelaboratory Instruction by Television and Film at the Ohio State University
I n one approach to the problem of maintaining a consistent high level of instruction in a general chemistry program, students a t the Ohio State University receive their prelaboratory instruction by an instructoroperated, departmental closed-circuit television system. Every freshman laboratory is equipped with 23-in. broadcast receivers located so that students standing a t their stations can comfortably see and hear the televised instruction. Each of the freshman courses has been assigned a regular TV channel and as many as three different courscs can simultaneously receive presentations. The central control point of origin, a small supply room adjacent to the laboratories, contains two 1-in. video tape recorders, a film chain, "live" TV cameras, and the necessary switching apparatus, R f modulators, etc. (see Fig. 2). A single coaxial cable connects the receivers in the laboratories to the control point. All equipment is operated by the freshman staff assisted by undergraduate assistants. The equipment is on throughout the day arid is used on a regularly scheduled basis in addition to any nonscheduled requirements of thc instructors. Materials used on the TV may be film or video tape, in addition to demonstrations performed live before a small TV camera. I n any case, the instructors prcpare all the materials, including graphics, and either perform the manipulations or operate the cameras, 746
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Journal of Chemical Education
as well as add the narrations. At the outset of t,he TV project, certain production formats were established; the purpose was to get away from the traditional "TV teacher" image and give the laboratory instructnr a useful tool which in no way displaced him as the principal authority in the laboratory (see Fig. 3). The lengt,h of the presentation is held t,o approximately 15 min, and consists of (1) introductory remarks which servc to orient the students' att,entinn towards a particular area of chemistry, (2) a statement of t,he experimental problem to be in-
Figure 3. The presentation. on TV the "individual view" and con$i,t of close-up pictures of loboratmy opparatur, occa9ionolly manipulated b y on unseen instructor's hands, in addition to graphics and animation.
vestigated, (3) a brief discussion of the approach to he used for investigating the problem, (4) the development of an experimental procedure, and (5) a discussion of methods for treating the data collected. Care is taken that data are not televised in a fashion that allows the student to anticipate the outcome of the ex.periment. Each segment of these laboratory introductions can he used independently. A telephone in each laboratory is connected to the TV center, and the laboratory instructor may call for segments of the presentation to be re-run if he feels a point was not well understood by the students. The instructor may also request that t,he TV presentation be delayed if additional introductory comments are necessary. Since there are three TV channels and only two courses meeting at t,he same time, the unused channel can be used by either course for staggering the instruction by replaying or delaying the TV into any given laboratory. In the original design of this program it was decided to put all the instruction for one course (Chem. 121122) on l6mm color film; such film can he played directly into the TV system or converted to video tape. Films are produced with an eye toward the future when out-of-lab assignments and distribution of materials to other campuses may he possible, in addition to capturing the best possible approaches to basic problems on a non-fragile medium. In these films particular advantage was taken of the "second look" that edited film affords to select the best closeups of basic laboratory techniques, including instrument or equipment reading, e.g., the 1/10 scale vernier on a laboratory barometer, the micrometer dial of the automatic analytical balance, etc. Elements of the films are also converted to video tape as required for two courses which are committed to preparing materials directly on video tape. The general format of "zero" angle (over the shoulder camera viewing angle), a standard background for both the Film and TV productions, and a narrative audio style facilitates the interchanging of elements between any film or tape in making up a complete TV presentation. The color films are projected in the weekly staff meetings for the undergraduate Teaching Assistants, at which time the elements of color essential to the picture which will he missing on the B/W-TV are noted in addition to an intensive discussion of the laboratory problem. A 16mm color film using A and B roll editing, which almost always must be used to produce animation effects, with magnetic sound can he produced for about $40/min as compared with $l/min for 1-in. video tape (excluding the costs of the production equipment, which in the case of TV is considerably more than for film). To minimize film production costs, films are made with a Bolex l6mm reflex camera which shares quality lenses with our TV cameras. The original film is developed, edge numbered, and stored at the film processors who return within 24 hr a color work print which the instructor edits. A magnetic stripe for narration is added to the work print for playing directly into the CCTV system using the film chain, or the film is converted to video tape. The film or tape is used for a quarter and carefully evaluated as to length and clarity of presentation, and, as necessary, new material is inserted or scenes are shortened or
removed. When the film is satisfactory to the Freshman staff, i t is sent to the film processor who matches the edge numbers on the original film to the workprint, which has wax-penciled editing instructions, and prints a complete film with optical effects, e.g., dissolves, superimpositions, and a magnetic stripe. The sound from the video tape or magnetic striped workprint may be transferred to this final print. 8-5 or 8mm copies are made from the film. Initially using the workprint for instruction rather than a completely finished film, as in the traditional film maker's approach, reduces the lengthy lead time necessary to produce the film, (to compete with the instant playhack advantage of TV) and the pressure to use the unevaluated, but expensive, "complete" professional film. I n addition to the convenience of instant playback, the economy of 1-in. video tape compared to 16mm film makes the TV-using the relatively simple cameras, special effects generators, switchers, etc.-attractive. In comparison to film, it is relatively easy to obtain special TV effects, e.g., superimposing or combining two images on a television screen using electronic image mixing devices, whereas these effects are difficult and expensive to produce on motion picture film. The economics of distributing the film image by TV to many laboratories is apparent. If an expansion or modification of the Ohio State system (see Fig. 4) were contemplated, color capability would be considered. The present TV distribution system will transmit the color signal. The video recorders can he modified to record or play back color, or new recorders such as the Bell and Howell model 2920 which have an inherent color capability could he used. The major deterent presently is the cost of color receivers, which would be about 3 times that of the B/W models. Presently, originating live color in this simple, closed-circuit television system, using the low-cost cameras, would require considerable engineer-
Figure 4. A schematic of the loboratory clo3ed circuit television system. The system conrittr d rtondord, easily available CCTV components, and special engineering support is not necessary to install this type of sy%tern. Pwameters for the distribution equipment ore avoiloble from the monufaduren (see Patt I1 of this series).
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ing support. However, as an alternate method, color films could be sent to video dubbing centers such as Video Flight Inc. (Sony) or Bell and Howell, or any portable video recorder can be moved to an educational broadcast station with a color film chain and the conversion to color video tape accomplished. The concept of presenting prelaboratory instruction by television at the Ohio State University has proved workable and satisfactory both for students and staff. The B/W equipment required is reliable, simple to operate, and inexpensive enough to be purchased by a deoartment. Future Developments
To utilize television more effectively in the future, projects to. design or rennovate classrooms or laboratories should take into consideration the installation requirements for receivers and projectors. In the chemistry classroom of the future, the authors see improved color television projectors; these devices will project an image as bright as existing 16mm film projectors, and the problems of reproducing color accurately may be solved by engineering concepts which will depart from the traditional 3 electron gun cathode ray tube (crt) now being used in all color receivers. The General Electric "light valve" color projector is an example of recent engineering advances in television projectors. This device electronically regulates a thin film which can be modulated in the light beam from a xenon light source. Since the thin film serves as a grating, the reflected light can be dispersed a t specific wavelengths and combined in an additive color system to produce a good quality color picture on a projecting screen. Problems in hue shift and color change which characterize present broadcast receivers are being reduced in many new receiver models. Stable tuners and automatic frequency controls reduce channel tuning problems (and thus color drift); modified designs in color picture tubes such as the Sony "trinitron" tube, which has a different configuration of electron color guns from American design, should further reduce these problems. The importance of auxillary inputs for TV receivers or projectors in the classroom or laboratory may become further evident when in addition to the portable video tape recorders, concepts which make multiple use of the cathode ray tube such as the CBS-EVR system, the Sylvania "Home theatre" concept, and computer graphic display controllers are available to the teacher. The EVR system will consist of a special 8mm film in a cartridge which has images transcribed from 16mm film or video tape, and a receiver attachment which converts the film image electronically to a form which can be played through the receiver picture tube. Advantages, of this system will include an unlimited stop-frame capability, color, and ease of edit,ing, in addition to the already proven convenience of having material available in cartridge form. The Sylvania home theatre concept combines a scanning device which allows color slides to be played through a receiver picture tube and an audio tape recorder, in addition to regular broadcast reception. Computer 748
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Journal of Chemical Edumfion
character/graph display generators such as the Computer Communications Model cc-301 can transform bit information from the computer into characters with the proper format and patterns which can be displayed on a standard broadcast receiver as alphanumeric or graphic data on any TV receiver or monitor. It is apparent from the experience with television a t the Ohio State University that a quality picture can he obtained on TV projectors as well as. in a simple, closed-circuit system using instructor-operated equipment. The fundamental element controlling picture stability and resolution in the system is the composite picture signal coming from the TV camera. The E.I.A. synchronized cameras3 used at Ohio State are expensive but contribute significantly to the solution of the problem of obtaining a quality picture a t a reasonable cost; new B/W camera designs hopefully can inexpensively incorporate the standards along with simple camera controls. Color television cameras to complement classroom TV projectors and laboratory receivers should be readily available within several years. The Bell and Howell (IVC format) color camera model 2970 and RCA model PIC-701 are examples of the trend toward inexpensive cameras requiring a minimum of complex adjustments to maintain color purity, etc. The solution to the fundamental problem of reproducing color accurately with adequate resolution depends on engineering breakthroughs, probably departing from the present camera designs, which nse 3 or 4 picture tubes, to use of a single camera picture tube and electronic coding devices. It probably will be several years before these significant design changes and marketing can make inexpensive color cameras available to the teacher of chemistry, who should remain critical of inaccurate or inconsistant color reproduction on TV. The transmission of television images by communication-type wire rather than by more expensive coaxial cable is anticipated. New ways of coding information for transmission on conventional phone lines using pulse code modulation or "slow-scan" transmission, for example, may significantly reduce the cost of picture transmission and facilitate the development of extensive chemical information systems within chemistry departments, or on a broader scale, within the chemical community. There is little doubt that the demands of increasing student enrollments and the trends toward improved visual introductions to chemical concepts and techniques will favor wider uses of instructional television in college chemistry. Although neither the hardware nor the uses of it have yet passed the experimental stage for college level educational purposes, both show a high potential for improvement and utilization in the near future. Careful and critical attention must be given to the equipment purchased for television instruction and, perhaps, even more critical attention must continually be directed at the content of the instruction planned and its optimum distribution between televised presentation and live teaching. Part I1 in this series, J. CHEM.EDUC., 45, 681 (1968)
We wish to acknowledge the leadership of W. B. Cook and W. T. Lippincott in the development of the instructor-centered television concept, and thitnk them for their encouragement in preparing this report.
Appreciation is also expressed to the Advisory Council on College Chemistry for partial support in preparing this three-part series on t,elevision
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