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.…

Illustrates advantages of research on practical factors in reasoning. Discusses role of factual knowledge and diagnosis of specific task-based errors in reasoning, influence of individual aptitudes on reasoning, and effect of educational interventions designed to change reasoning. Presents Piagetian position for each position, discusses evidence…