1979 Volume 19 Issue 2 Pages 29-34
According to the Piagetian theory, it is said that children aquire the conservation concepts of quantity in the invariant sequence, as they grow from 7 years old to 12 or 13 years. The sequence is, as well known, the conservation of substance, weight and volume. Before the conservation of volume has been aquired by children, they have to pass through the stage in which they can discriminate between two concepts of weight and volme. In this study the author has intended to survey the children's ability to do these discriminations in the various situations for the pupils from 4th grade to 7th grade, using the written quetionaires formulated by the author. The subjects employed were 400 to 500 children in each grade selected ramdomly from elementary schools and junior high schools in Tokyo. The data obtained were processed statisticaly and dicussed fully. One of usefull findings of this study is that there were many children even in the seventh grade who could not discriminate between two concepts of weight and volume.