| Abstract: | Approximately one-half of the fifth through eighth graders in a school district (n = 164) were randomly selected to be administered a group test of disjunctive reasoning containing 48 inclusive and exclusive items varying in content of the premises (symbolic, object, and human), and affirmation or negation of the conclusion. Using an analysis of variance for repeated measures it was found that performance improved until seventh grade. Eighth graders scored similar to sixth graders. There was a main effect for negative, with negative conclusions producing more correct answers. Further, there were significant first order interactions for Disjunctive by Negation, Content by Grade, and Negation by Content. Since either “YES” or “NO” were the only correct answers, and “MAYBE” was always wrong, contrast of the MAYBE responses to other wrong answers revealed an increasing tendency to use MAYBE among older subjects. Implications were discussed in relation to cognitive developmental theory and educational practices. |
