New-Piagetian theory has proposed that mental capacity and mental demand do a critical role in human cognitive processes. In this study, the students` mental capacity and the mental demand of the given problems were examined. The principal findings of...
New-Piagetian theory has proposed that mental capacity and mental demand do a critical role in human cognitive processes. In this study, the students` mental capacity and the mental demand of the given problems were examined. The principal findings of the study are as follows; (1) There was no significant difference among achievement scores of subjects (3rd grade students of middle school, 2nd grade students of high school, 3rd grade students of high school) in the items of balance that needed specific content knowledge. But, in the Newton`s 2nd law items that needed specific content knowledge, there was significant difference be ween 3rd grade students of middle school and high school students(2nd, 3rd). According to increase of mental demand, middle school students` achievement score appeared to decrease linearly. However high school students` achievement score didn`t change until they faced the items of critical mental demand. When mental demand was beyond critical mental demand, their score was decreased rapidly. (2) According to hierchical analysis of items, the more mental demand an item needed, the higher or at lest the same hierachical item was. These results showed that mental demand was the main factor which decided difficulties of problem solving. (3) It was possible for students to solve the newton`s 2nd law item that had one or two more mental demand relative to balance beam item. Although the item needed the same mental demand, students recognized that the Newton`s 2nd law items were easier than the balance beam items.