Twenty-three high school biology students were individually administered three conservation tasks (weight, volume, volume displacement). During one semester, they were examined over the course material using published Biological Sciences Curriculum Study (BSCS) Blue Version examination questions which were previously classified as requiring either…

Some evidence supports the hypothesis that formal operational reasoning ability (at least that measured by Piagetian tasks) is a unified process. The purpose of this research was to determine: (1) if conservation tasks, such as conservation of number, liquid amount, weight and volume, are unifactor; and (2) if conservation tasks form a scale of…