Students were classified as formal or concrete-operational using a battery of Piagetian tasks, a biology content examination, and a nonscience content examination. Based on the results it was concluded that Piagetian tasks are relatively content-free and can serve as realistic indicators of concrete and formal thinking abilities. (MLH)

There is considerable disagreement concerning the age of onset and universality of attainment of Piaget's stage of formal operations. This study examines developmental differences in response to brief prompts in the use of a formal operational approach to the solution of two tasks. The subjects were 10 males and 10 females from each of Grades 5,…

A major premise of Piagetian theory relative to the periods of concrete and formal operations is that competence in specific logical operations is a necessary but not sufficient prerequisite to competence in other specific logical operations. The present study tested for the existence of specific concrete operations and specific formal operations…

The reasoning ability of 20 ninth grade, 20 eleventh grade, and 15 college freshman boys was explored. Three tasks in reasoning were given each student. In the "turtles task" the student was asked to test a hypothesis; from his responses the investigator determined whether the student tested the hypothesis by trying to find confirming instance or,…