Two selection and nine evaluation hypothesis testing tasks varying systematically with respect to causality, response alternatives, and context continuity were administered to two samples of adults (N=35; N=32). It was to determine effects of these variables and the degree to which subjects reasoned with material conditional, biconditional,…

Compared laboratory and naturalistic content influences on formal reasoning tasks of 90 13-, 15-, and 17-year-olds, focusing on tasks requiring ability to control variables. Results indicate that 8 to 20 percent of performance variance was associated with task content. Content effects were also shown to reflect expectations about task variables.…

Examines content and problem effects of formal thought in 13-year-olds (N=120). Three controlling variables tasks with different content and two question-type tests (analysis and controlling questions) were administered. Findings, among others, indicate that content and problem effects contribute to variance on formal reasoning problems.…

Twelve pupils from each of 13 middle school science classes participated in this study. Findings, among others, indicate that two of nine engagement measures (attending and generalizing), together with formal reasoning ability, were related to process skill, achievement, and retention. (JN)