A sex-related difference, favoring boys, was found on initial performance of two samples (one British, one American) of 10- and 11-year-old children on tasks involving volume and density. After classroom instruction that included opportunities for interaction with appropriate materials, both sexes performed at higher levels but differences…

Determined that males (N=70) demonstrate higher level of intellectual development than females (N=70), that males mature intellectually earlier than females, and that there appear to be factors other than age and sex that are related to development of formal operational reasoning. Implications of these and other results are discussed. (JN)

Determined the degree to which classification of students (N=512) as formal or concrete based on three Inhelder tasks administered by clinical interview method was mirrored by Longeot and Karplus-Lawson-Renner (KLR) classifications. Results indicate that Longeot and KLR differentiate between concrete/formal operations and are discussed from…

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)

Effect of science instruction on young children's (N=64) concept of Piagetian physical causality was investigated. Results indicate, that pre/concrete-operational children can learn and apply a definition of living when that definition is taught through observable characteristics. Additional results and implications for elementary science…