Purpose & Method. Our purpose was to inquire into the differences of the results produeced on the effectiveness in learning, with the way of distinguishing minerals as the subject for our study. The experimental lessons were conducted in four different groups as follows : The first group used the textbook and the charts in it (Contrast Group), the second group used color photographs in addition to the textbook and the charts in it ; the third group learned the lesson through the observation of mineral objects in addition to the textbook and the charts in it, and．the fourth group studied thelesson through the measurement of the hardness of the minerals in addition to the textbook, the charts init, and the obseryation of mineral objects (Experimental Groups).
Results.(1)In the answers in the paper test concerning the color and hardness of the minerals, the contrast group showed a little better results than those shown by the other experimental groups. And in the results of the distinction of the objects, hardly any difference was noticed between the contrast group and the experimental groups. However, it is to be noted that the number of the test questions was coincidentally the same with the number(6 kinds)of the minerals which the students studied in the textbook. Also it may have something to do with these results that the measurement of the hardness of minerals was done only in one or two cases. (2)The number of the students who said, "The lesson was easy to understand, "or who said, "The lesson interested us, " was greater in the experimental groups than in the contrast group.