Problem solving has been a concern of science education for at least three quarters of a century. This book presents a comprehensive review of the research that has occurred in problem solving. The studies included in this summary range across the continuum. Some are concerned with gaps between conditions and resolutions; some involve science process skills; most in one way or another involve classroom exercises. All have in common a concern for problem solving in the science classroom. Although the primary concern in this summary is with science at the middle grades, some studies that extend into the elementary grades and into the high school years have been retained. Major sections of this book include definitions of problem solving, the assessment of problem solving, problem solving strategies and behaviors, gender differences, cognitive style and problem solving, cognitive development and reasoning ability, instruction and problem solving, and science curricula. (Contains over 130 references.) (PR)