Reports a study of 922 college students that classified the students based on performance on formal operational reasoning tasks. Students were also administered seven logic tasks. Response patterns were analyzed and found to be similar to patterns derived from the multiple-hypothesis theory of advanced scientific reasoning and different from those…

Developmental assumptions that are frequently regarded as constraints on elementary school science curricula are analyzed. The argument that elementary school children cannot function as experimentalists because they have not yet attained formal operational thought is not supported by the Piagetian or non-Piagetian research reviewed. (SLD)