This process accomplishes a gradual and comprehensive replacement of the indistinct general terms by the technical ones. "Filament" replaces "fine wire"; "emit" takes the place of "glow" and "give off light", and then the word "emit" is inflected in different ways for greater familiarity with terms.
Such a program must be very carefully worked out to avoid ambiguity and to escape incorrect but justifiable answers. For example in number three, the words heat and are necessary to make heat impossible for the answer. It is probably harder to compose such a program than it is to cover the same material in a textbook passage. The machine material must be clear and self-contained, because the machine is the only source, and cannot clarify itself as a teacher can.
"Textbooks," Skinner remarked, "are of little help in preparing a program. They are usually not logical or developmental arrangements of material but strategems which the authors have found successful under existing classroom conditions. The examples they give are more often chosen to hold the student's interest than to clarify terms and principles. In composing material for the machine, the programmer may go directly to the point.
Actually, of course, it is wrong to say that the machine does any teaching. It just presents the material in a logical way, conveys knowledge from the composer of the program to the student. Of course it is infinitely more efficient than a real teacher, since the number of students to whom it can convey this information is virtually limitless.
Professor Skinner says that in many ways his teaching machines are like individual tutors, and indeed the machines seem more accurate than many of its rivals in Cambridge. He points out that there is a continual interchange between the program and the student, and that since the student is always active, manipulating the machine, he avoids the stupor of textbook-reading or lecture-drowze. Skinner points out that, "like a good tutor, the machine insists that a given point be thoroughly understood, either frame by frame or set, before the student moves on." And perhaps most importantly, the machine, like a good tutor, substantiates and corroborates right answers and quickly points out and corrects wrong ones--"using this immediate feedback not only to shape his behavior most efficiently but to maintain it in strength in a manner which the layman would describe as 'holding the student's interest.'"
The greatest virtue of the machines is that, by all the admittedly scanty information on their effectiveness, they seem to put knowledge into a student's head and to make the knowledge stick with much less trouble and time than either books, audiovisual aids, or lectures. In Nat Sci 114 last year, in which forty-eight of the machines' disks replaced the textbooks, the average time spent at the machines to complete the forty-eight disks (equivalent to nearly a whole semester's reading) was about fourteen and a half hours. Comprehension did not suffer. Eventually the text was read too, for comparative purposes. To the question, "In comparing work on the machine with studying the text, I felt that with the same time and effort," thirty-two per cent of the students said that they had learned "much more" on the machine, and forty-six per cent said they learned "somewhat more" on the machine. Seventy-seven per cent of the students said, "I would have got less out of the course if machines had not been used."
The real asset of teaching machines, of course, and very likely the reason so much money is being spent now on their research and development, is the terrific dearth of teachers in this country. If teaching machines could be run off assembly lines as just another gadget and someday became as common as television sets, the few teachers there are could be liberated from the more ponderous tasks of mechanical instruction they now have to perform, and the dilemma of the teacher shortage could be substantially diminished, if not wiped out entirely.
Problems Presented
The time is not so far off as one might think, but the idea of machines for teaching brings up many problems not noticed at first glance. Grading systems would probably have to be greatly revised; the entire concept of education by coercion, motivation, threat and sweat would have to be reexamined; and the application of scientific principles to secondary education would have to be considered. Professor Skinner himself has said: "In the light of our present knowledge a school system must be called a failure if it cannot induce students to learn except by threatening them not to learn." A study of education within the structure of the modern science of behavior does indeed have broad implications.
Harbinger of New World
Whether or not the teaching machines, in a generation or so, will become a major weapon in winning the battle for western technological supremacy; whether or not they will someday help equalize the supply of teachers with the demand; certainly that row of ten silent machines in Sever Hall is a harbinger of a nervous and not too brave new world.