This review presents a broad perspective of the state of knowledge in science education, a description of existing trends, the areas where research is needed, and tentative answers to persistent problems that have been identified from the research. The review is organized into eight sections. An introductory section describes methods of using research to understand the science learning context. Five following sections focus on research dealing with the elementary school student, the emerging adolescent, the adolescent, the undergraduate college student, and the science teacher. The last two sections deal with measurement instruments used in science education, and an historical perspective relating science education research of 1979 to that of the past and discussing trends and implications for future research. (CS)