Abstract
With simultaneous instruction we can't fully expect to teach pupils according to their individual abilities and speed of understanding. To overcome this difficulty, we have introduced STUDY BOX (individual learning apparatus ). In continuation with the papers (1), (2) and (3),we have made a follow-up on the effects of curative measures by STUDY BOX; and in the present paper, we have followed up the research. As a result, we have found that the study using STUDY BOX is effective to cure errors. Moreover, we can detect through follow-up examinational few pupils who need more individual instruction. Consequently, we are able to give these pupils a thorough individual instruction.
