The intent of this publication is to consolidate and critique research findings related to teaching and learning in the sciences as they were reported in 1990. The purposes of this and previous summaries include: (1) providing an overview of recent research activity for scholars in the field; (2) providing research information in succinct form for practitioners and development personnel; (3) stimulating ideas for further research; and (4) tracking trends in science education research. In 1990 there was increased reporting of research on conceptual change, problem solving, assessment, and women and minorities in science education. Researchers in science education appear to be using an increased variety of research methods including: standard experimental studies, ethnographies, in-depth clinical interviews, philosophical analyses, surveys, Delphi studies, and cost-effective analyses. The book is divided into the following categories: Conceptual Change and Achievement; Problem Solving; Science Process/Inquiry Skills; Cognitive Development and Logical Reasoning Skills; Assessment and Research Design; the Nature of Science; Science, Technology, and Society; Curriculum and Instructional Intervention Studies; Student Attitudes and Preferences; Equity Issues and Science Education; Students with Special Needs; Teacher Characteristics; Teacher Preparation; Policy Studies; International Science Education; Uses of Technology; Analysis of Science Textbooks; and Informal Science Centers. (More than 200 references) (PR)