标题:428 場面・集団活動に関する一考察 : 物媒介の対人関係活動のもたらす場面転換について (日本教育心理学会第4回総会部門別研究発表要旨・討論の概要 : 12. 集団力学・学級集団) [in Japanese] 428. A study on the group-situation activities : on the change of situation caused by the person-object interaction. (TITLE OF PAPERS AND THE SUMMARIES OF DISCUSSIONS : 12. Group dynamics and classroom groups) [in Japanese]