Purpose As one of the series of studies concerning the results produced on the effectiveness in learning by the structure of the contents of the lesson, the present research was conducted with the mechanism of transmission of power in the bicycle as the subjects. The experimental lessons were conducted in two major groups : One was the control group who learned the lesson mainly through the textbook (M+P) whose contents were composed of the Method (M) (= mechanism) and Purpose (P) (= function), and the other was the experimental group who learned the lesson, besides the study of the Method and Purpose, through the additional learning of another element, Ground (G) (= principle), which constitutes the three elements composing technology. This latter group was further divided into three subgroups as shown below. Thus the experimental and substantiative analyses were made of the difference in the results produced on the effectiveness in learning between the two groups. Method As shown below, with the mechanism of the transmission of power in the bicycle as the subject, the four different types of experimental lessons were conducted at Junior High School attached to the Faculty of Education, Shimane University [M + P : the mainly-textbook-taught learning ; G・M + P : the learning of the principle (the moment of rotation) before the mainly-textbook-taught learning ; G + M + P : the principle-learning and the mainly-textbook-taught learning were in close connection ; M + P・G : the learning of the principle after the mainly-textbook-taught learning].
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Group Structure of the contents Learner
of the lesson

Control (a) M + P 23 boys of 2nd Year, Class I
┌ (b) G・M + P 20 boys of 2nd Year, Class II
Experimental ｜ (c) G + M + P 22 boys of 2nd Year, Class III
└ (d) M + P・G 24 boys of 2nd Year, Class IV
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No significant differences were noticed among the four groups in the d ifferential inintelligence.
Results Compared with the students of the control group, those of the experimental groups (1) showed better results in their grasp and understanding of the contents of the lesson, based on the standpoint of the principle and (2) tended to show easiness of a general grasp and understanding of the contents of the lesson.