28.3 Audio Technology
Early educational technology such as the radio, the telephone, the tape recorder, and the loudspeaker attracted the attention of researchers. Loder (1937) compared the retention of factual materials presented over a loudspeaker system and directly by a speaker. Two groups totaling 449 students were rotated in the experiment. A pretest, a test immediately after the lesson, a test I day later, and one 20 days later were given. One group saw the speaker, and the other group heard him from another room. The direct group performed better, but later tests showed that the means were not significantly different.
Cook and Nemzek (1939) compared the effectiveness of radio instruction and conventional teaching. Two intermediate school groups were match-paired by age, sex, and intelligence for this experiment. Pretests and posttests were given. Their results showed a superiority for the radio-taught classes.
Rulon (1943a), using phonographic recordings, conducted an experiment to compare the amount of information gained by students who listened and those who studied the same material in printed form. Time was equalized. A total of 418 students listened to the recordings; 426 students studied the printed material. All students involved took a pretest, a posttest, and a test I week after the experiment was completed. Separate t tests were used to compare means of the pretest and posttest and also the delayed test. According to Rulon, the study of the printed material was superior to the method employing the recordings. However, a comparison in tests taken after a week showed little difference in methods employed. From this result, he concluded illogically that recordings make more of a lasting impression than printed materials.
Rulon (1943b) later conducted a similar experiment to compare the amount of information gained by students using phonographic recordings with the amount gained by students who studied a unit incorporating the same material presented in a textbook. This experiment probably is closer to an actual classroom situation, although, in this case, the textbook was prepared using the recordings as a primary source. Instructional methods using the textbook were not controlled. Testing procedures were similar to those above. The results, also using the t test, showed that phonographic recordings failed to show any superior effectiveness in teaching the "informational" aspects of the lesson.
In a third study on the effects of phonographic recordings, Rulon (1943c) investigated the motivational values of recordings. Using the same recordings and textbooks prepared for the earlier experiment, two groups of students were given access to supplementary reading materials after one group had heard the recordings and the other had read the material. Motivation was measured by which group used more supplementary reading materials. A total of 193 students used the recording, and 187 used the textbook presentation. Rulon's study showed no difference between the groups in terms of motivation to use supplementary reading material.