[The effects of knowledge and its developmental differences on misconception of weight]

This study aims to examine developmental knowledge related to misconception about weight. Subjects from 5th to 7th graders were asked to reason about justifiable phenomena which never occur in science. After that, before judging weight addition tasks, subjects engaged in some knowledge-generating-tasks to examine which knowledge-generating-tasks relate to misconception. The main results were as follows: (1) Most subjects did not realize untruth about justifiable phenomena, (2) the knowledge which related to misconception were muscular-kinetic-feeling and balance-feeling about weight, and (3) awareness to knowledge-generating-tasks changed with age; 5th graders found the relation about every kind of knowledge-task on chance level responding and 6th and 7th graders found the relation with some justifiable knowledge. Additionally, some 7th graders were not deluded by any knowledge-generating-tasks. These results suggested misconception about weight might relate to inference from some kinds of everyday-knowledge without realizing the inconsistency with science to them. The developmental change of awareness to knowledge-generating-tasks were discussed in terms of coordination subjects' own theory and their use of knowledge.