Administered five Piagetian tests to 180 adolescents for comparison to similar samples from 1967 and 1972. Found that today's adolescents exhibited higher levels of cognitive development than did previous cohorts. Gain varied across tasks, being very large for combinatory thought but mixed for conservation. This acceleration of cognitive…

A 1-year lag was found between the effect of an intervention intended to promote formal operational thinking in students initially 11 or 12 years of age and the appearance of substantial science achievement in the experimental groups. A one-year lag on cognitive development and an age/gender interaction were also reported. (Author/KR)

The purpose of a study was to explore the link between conceptual understanding, free exploration of hands-on science center exhibits, and Piagetian cognitive developmental levels. In this primarily qualitative study, which is based upon interview and observational data, patterns in children's behavior relating to specific hands-on science center…

To test whether gains in cognitive development can be accelerated, an intervention model was used to give pupils special lessons in science, using ideas of cognitive conflict, metacognition, and bridging in the context of formal operations. Found that intervention led to substantial and long-lasting increased achievement in science, mathematics,…