Extends prior theory and research by postulating the existence of an intermediate class of concepts called 'hypothetical'. Investigates the hypothesis that three kinds of scientific concepts exist by constructing and administering a test on concepts introduced in a college biology course. Supports the hypothesis that intellectual development…

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 if student questioning skills could be taught within framework of an ongoing chemistry course and if acquisition of these skills depends on high school students' (N=108) level of intellectual development. Results indicate that questioning skills can be acquired by students, regardless of their level of Piagetian intellectual…

Two years after the end of a two-year intervention program set within the context of science learning intended to promote formal operational thinking, achievement of students (n=234) was tested by their results on British National examinations taken at age 16. Male experimental subjects achieved an average of 40 percent more grades of C or above…

Discusses whether formal thought constitutes a structured whole and role of propositional logic in advanced reasoning. Presents aspects of advanced reasoning model, considering hypothesis generation/testing as central processes in intellectual development. Argues that advanced reasoning schemata are linked by these processes and should be…

Describes a set of Science Reasoning Tasks which are valid and reliable for assessing the ability of children to use concrete and formal reasoning strategies and can be used by science teachers without professional training in Piagetian studies. Thirty pupils can be tested on each task in about 50 minutes. (Author/DS)

Assessed the effect of a one-semester college biology course on the development of students (N=72) ability to reason formally and interactions among intelligence, cognitive style, and cognitive level. Includes implications for science instruction. (SK)