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…

Describes a Skill Development Module fostering students' scientific reasoning skills within a school science laboratory. Summarizes the module activities in combination with computerized and non-computerized activities for a 16-week period. Discusses the classroom evaluation of the module. (YP)