Before 1920 
  The Future

  The 1920s:
Concepts of Objectives

Sidney Pressey

In the early 1920s Sidney Pressey, an educational psychology professor at Ohio State University, developed a machine to provide drill and practice items to students in his introductory courses. Pressey (1926, p.374) stated, " the procedure in mastery of drill and informational material were in many instances simple and definite enough to permit handling of much routine teaching by mechanical means." Pressey maintained that the teacher is "burdened by such routine of drill and information-fixing" (p. 374). Pressey further stated that this mechanical device could:

Lift from her [the teacher's] shoulders as much as possible of this burden and make her free for those inspirational and thought-stimulating activities which are, presumably, the real function of the teacher. (p. 374)

The teaching machine that Pressey developed resembled a typewriter carriage with a window that revealed a question having four answers. On one side of the carriage were four keys. The user pressed the key that corresponded to the correct answer. When the user pressed a key, the machine recorded the answer on a counter to the back of the machine and revealed the next question. After the user was finished, the person scoring the test slipped the test sheet back into the device and noted the score on the counter.

Pressey was directly influenced by Edward Thorndike, an educational psychologist at Columbia University Teachers College. Thorndike wrote in 1912:

If, by a miracle of mechanical ingenuity, a book could be so arranged that only to him who had done what was directed on page one would page two become visible, and so on, much that now requires personal instruction could be managed by print. (p. 165)

It was in these words that Edward Thorndike described the premise of computer based instruction half a century before the feasibility of such a system became possible. Thorndike's ideas of the textbook's purpose lend themselves well to using the computer as a tool for learning. Thorndike stated:

A textbook can do much more than be on the one hand a mere statement of the results of reasoning such as the ordinary geography or German grammar is, or on the other hand a mere statement of problems, such as the ordinary arithmetic or German reader is. (p. 165-166)

Pressey also noted that the most valuable and interesting purpose of his machine was to teach. Raising a lever on the back of the machine shifted the mechanism so that the user had to select the correct answer before the next question was revealed. Pressey (1926) stated that this immediacy of feedback makes the device "still more unusual" (p. 374). He also cited the fact that the question remains before the user until the correct answer is selected.

The influence of Thorndike on Pressey was substantial. Thorndike specified three conditions that maximized learning: the laws of recency, effect, and exercise. The law of effect stated that the likely recurrence of a response is generally governed by its consequence or effect generally in the form of reward or punishment. The law of recency stated that the most recent response is likely to govern the recurrence. The law of exercise stated that stimulus-response associations are strengthened through repetition.

In his machine Pressey sought to incorporate Thorndike's laws. In one version of his machine, a user had to answer a question twice correctly before it was eliminated; this addressed the laws of exercise and effect. Pressey (1927) stated:

Last the law of recency operated because the last answer chosen was the correct one. The correct response must almost inevitably be the most frequent, since the correct response is the only response by which the learner can go on to the next question, and since whenever a wrong response is made it must be compensated for by a further correct response. (p.551)

Pressey also believed that his machine provided the user with immediate knowledge of the results.

Pressey is credited with introducing the mastery learning paradigm into his machines by Pagliaro. Pagliaro also noted that Pressey "programmed" individualized instruction into his machine because the question was kept before the user until the correct response was selected and the question was eliminated as the correct answer was mastered.

In an article written in 1932, Pressey stated that "education was the one major activity in this country which has thus far not systematically applied ingenuity to the solution of its problems" (p. 668). He was confident that the machine he developed would lead to an "industrial revolution in education" (p. 672).

Pressey's revolution was delayed by the Great Depression. In the same year that Pressey predicted the revolution, the unemployment rate climbed to 23.6 percent, and new developments in educational technology were delayed until after World War II.

Skinner attributed the failure of Pressey's machines to the fact that the world of education was not ready for them. He also noted that Pressey's machines were designed to be used after some learning had taken place elsewhere.

By confirming correct responses and by weakening responses which should not have been acquired, a self-testing machine does, indeed teach; but it is not designed primarily for that purpose. (p. 969)


Pagliaro, L.A. (1983). The history and development of CAI: 1926-1981, an overview. The Alberta Journal of Educational Research, 29 (1), 75-84.

Pressey, S.L. (1926). A simple apparatus which gives tests and scores - and teaches. School and Society, 23 (586), 373-376.

Pressey, S.L. (1927). A machine for automatic teaching of drill material. School and Society, 25 (645), 549-552.

Pressey, S.L. (1932). A third and fourth contribution toward the coming "industrial revolution" in education. School and Society, 36 (934), 668-672.

Skinner, B.F. (1958). Teaching machines. Science, 128 (3330), 969-977.

Thorndike, E.L. (1912). Education: A first book. New York: The MacMillan Company