title: The Relation Between Two Kinds of U-Shaped Growth Curves: Balance-Scale and Weight-Addition Tasks.
abstract: Researchers have observed a U-shaped growth curve in the performance of weight-addition tasks (Aoki, 1988, 1989; Ginbayashi, 1975; Piaget, 1973). Aoki found that sixth graders performed poorly, mainly because they used the analogy of a seesaw (when we sit on a seesaw, the closer we sit to the end, the more the effect of our weight increases) to answer the questions. In the present study, the relationship between considering two dimensions on a balance scale (Siegler, 1976, 1978) and performance in weight-addition tasks was examined. Fourth-, sixth-, eighth-grade, and college students performed weight-addition tasks, which were presented in a paper-and-pencil format. The results showed that considering only one dimension facilitated their performance only on the one-dimensional task. The reason sixth graders' performance dropped in the weight-addition tasks was not clear, however.
authors.affiliation: a Faculty of Education , Kyushu University , Japan.
authors.forename: Tazuko
authors.initials: T
authors.lastname: Aoki