抄録
As weight is invisible, some judgmental criteria are needed in judging weight. An experiment was carried out using the second, forth, sixth, eighth graders and college students to reveal (1) what weights positions make subjects more errors in judgment of weights addition and (2) what relationships will be found between the judgments and judgmental criteria. Subjects were engaged in the tasks to judge weights addition in two conditions, height of weights and relative positions, and were asked the judgmental criteria in two situations, visual exteroceptive and realistic proprioceptive situations. Results showed clearly the developmental changes. The fourth graders dominatly produced errors in height of weights conditions and tended to depend on the criteria in realistic situations. In the contrast to this, the eighth graders committed errors in relative differences of weights positions and depended on the criteria in visual situations as well as realistic ones. Sex differences were also observed in terms of criteria. No relations between the judgments and judgmental criteria was found in girls' judgments of weights additions.
