Proposes a theoretical model of cognitive development and applies this model to the secondary analysis of two large-scale studies which focus on the acquisition of formal operational schemata by adolescents in the United States and Israel. Results support the "unity" hypothesis of cognitive development that the various schemata of formal…

Reports a study of 922 college students that classified the students based on performance on formal operational reasoning tasks. Students were also administered seven logic tasks. Response patterns were analyzed and found to be similar to patterns derived from the multiple-hypothesis theory of advanced scientific reasoning and different from those…

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…

Reports a study that analyzes the importance of individual difference variables in explaining subject performance in formal reasoning in 72 first-year college students. (PR)

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 effect of intervention lessons designed to accelerate the development of formal operations taught over a period of two years to adolescents was assessed. Results indicated that the experimental group had achieved a significantly greater gain in cognitive levels than the control group. Implications are discussed. (CW)