Talk About Teaching ------------------- Technology in Teaching ====================== by C. J. McMahon, Jr. Suppose that you, as an automotive expert, are given the task of explaining how the basic parts of an automobile work to a student with a good high school education. You want to do this with maximum effectiveness in the minimum time. You quickly realize that a chalkboard is inadequate and that you need to employ visual aids, like diagrams and photographs. Ideally, you would want to use animated illustrations of the various parts of the engine, transmission, drive shaft, steering, brakes, etc., perhaps along with photographs and video clips. At the moment, there is no way to do this, but in the brave new world now almost upon us, you could load a CD-ROM into your laptop computer (color screen, of course), let the student play it, and then be there to answer questions and elaborate on whatever points need more explanation. The need for this kind of teaching abounds in many areas of pure and applied science. As a "high-end" educational institution, our challenge is to be at the leading edge of teaching with maximum efficiency and effectiveness. That is, in the limited time available for any given subject we need to impart the maximum amount of knowledge and understanding at the highest possible level. If we succeed, we will continue to attract highly intelligent students willing to go into debt (along with their parents) to study here. The way to succeed is to take advantage of the technology now available, technology which will be part of routine teaching within the current decade at any institution at the leading edge. Our introductory course in materials science has been a good test bed for the development of techniques for teaching about complicated systems which are completely unfamiliar to the average beginning student. The aim of the course is to provide in one semester for any undergraduate with a decent high school education a functional understanding of the discipline, which essentially involves the relationships connecting properties of materials (i.e., metals, ceramics, polymers, composites, and semiconductors) with their structure, ranging from the electronic level to structures coarse enough to see with the naked eye. We have just finished a seven-year development effort, which culminated in a new textbook in which we reformulated the traditional list of topics in a way that provides a student with a familiar conceptual framework. Dividing materials into those used to build structures and those used for devices, we use the bicycle and the Walkman as our paradigms. We have found that we can not only improve greatly on the students' understanding and retention but also raise the level of the course to a considerable degree. While we were in the middle of this effort, it became apparent that it would be necessary to develop better ways to overcome the barriers to understanding of topics that require students to visualize complex phenomena, like the operation of the parts of an automobile. Many of the phenomena of interest involve physical motion or things that evolve with time. We found that static illustrations are inadequate to convey an accurate mental picture of the processes involved. This realization came from a number of informal review sessions, usually held before mid-terms or final exams, in which students were encouraged to explain their understanding of various topics. The fundamental problem is that, when an instructor attempts to convey a complex mental picture, he has no way to see the image that the student has received and the student cannot see the image that was being transmitted. The solution to this problem is obviously to use a computer monitor, so that the dynamic image of the phenomenon or process is visible on the screen to both the instructor and student simultaneously. This is analogous to a high-tech chalkboard or slide projector; the essential difference is that the image can be made to move. We have found that this method produces an extraordinary improvement in the speed and accuracy of comprehension of complex topics. The effect is at least as great as one would find from the use of normal (static) illustrations, compared with no illustrations. A good example is found in the series of animations depicting the plastic shearing of crystals by the motion of defects called dislocations. In about forty minutes, we can convey an accurate understanding of this set of phenomena, which are normally considered too complex for an introductory-level course. Without the animations, it would take at least twice as long to "cover" this subject, and we would have no idea of how much was comprehended by any particular student. A clear understanding of the mechanisms of plastic deformation is essential for one to learn how materials, e.g., in bicycles are made strong. Thus, a major part of the course is on shaky ground if the student does not understand the basic ideas of dislocations. Beyond `Shovelware' The improvement in communication allowed by the animations is analogous to the advance provided by cinematography over still photography. Once animations are used, it becomes unthinkable not to continue to use them on a more extensive scale. Thus, they define a new state of the art. The problem then becomes one of assembling the money and talent to produce computer-based dynamic images on an ever-expanding scale. This involves the right kind of computer (e.g., a Quadra AV-type) with lots of memory, software like Macromedia Director, video-editing hardware and software, a machine to make CD-ROMs, etc., along with an instructor who is an experienced teacher and has a clear understanding of the images that need to be produced and one or more assistants who are capable of using the equipment to produce the images. All this involves the acquisition of new resources, or the re-allocation of present resources, at a time when financial pressures are increasing. However, there is really no choice for a university that wants to be competitive in the long run, and the long run will be measured in years, not decades. It needs to be emphasized that the type of activity being described here is separate from the ideas being discussed with regard to distance learning via the Internet, the so-called virtual university. We are speaking here simply of a logical extension of what already goes on in university courses, using new hardware and software. Producing this type of CD-ROM is essentially similar to authoring a textbook of a type that needs a lot of technical assistance. That is, it needs the participation of specialists who keep up to date in a fast-developing new field. Because of this, carefully thought out institutional support would be of great benefit. It would be helpful to have a centralized resource at this University to provide this. The Center for Advanced Instructional Media at Yale might be an appropriate model, and the Annenberg School would seem to be a natural home for such a center, since what is involved here is essentially an advanced form of communication. Even though we at Penn would be a bit late arriving at the starting gate, we would not be very much behind the state of the art. The rate-limiting step in making a useful CD-ROM is the creation of useful content. Although the number of CD-ROM titles has grown in the past two years from under 200 to over 2000, the vast majority of titles are derided as "shovelware," for which images and text have been assembled from whatever lay at hand, just to get a product on the market. Since the creation and conveying of intellectually significant content is our main activity, we are in a clear position of advantage in entering this new field. This article is the sixth in a series developed by the Lindback Society and the College of Arts and Sciences. The author is professor of materials science and engineering in the School of Engineering and Applied Science.
Almanac
Volume 41, Number 25
March 21, 1995
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