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 large proportion of college students majoring in science are unable to translate even simple sentences into algebraic equations. Given the following sentence, "There are six times as many students (S) as professors (P) at this university," 37% of 150 freshmen engineering students in a study conducted in 1981 by Clement, Lockhead, and Monk wrote…

Reports on a study designed to determine the effectiveness of two video programs with an audience of varied ages, grade levels, and developmental levels. Indicates that a significant difference was found between concrete, transitional, and formal operational students on pretest scores and developmental levels and results on the posttest. (RT)