Five items requiring use of proportional, probabilistic, and correlational reasoning were administered to students (N=391) in grades 6, 8, 10, and 12. Argues that successful qualitative reasoning arises as a consequence of equilibration and influences selection of course work and that specific instruction may initiate the equilibration process.…

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.…

In this article, the author gives a general introduction of a few ideas on cognitive development in children. In the first part, he deals with the topic of development, a process which concerns the totality of the structures of knowledge. He reviews the stages of development of operational structures, distinguishes four main stages of development,…