The National Science Education Standards present a vision of a scientifically literate populace. The standards outline what students need to know, understand, and be able to do to be scientifically literate at different grade levels. They describe an educational system in which all students demonstrate high levels of performance, teachers are empowered to make the decisions essential for effective learning, interlocking communities of teachers and students are focused on learning science, and supportive educational programs and systems nurture achievement. After an introductory chapter and a chapter that outlines the overarching principles that underlie the vision of scientific literacy for all students, the National Science Education Standards are presented in six chapters. The standards for science teaching presented in Chapter 3 focus on what teachers know and do. Chapter 4, "Standards for Professional Development for Teachers of Science", focuses on how teachers develop professional knowledge and skill. The standards in Chapters 3 and 4 present a broad and deep view of science teaching that is based on the conviction that scientific inquiry is at the heart of science and science learning. The science education assessment standards are presented in Chapter 5 as criteria for judging the quality of assessment practices and apply equally to classroom-based and externally designed assessments and to formative and summative assessments. The content standards, organized by K-4, 5-8, and 9-12 grade levels, are found in Chapter 6. These standards provide expectations for the development of student understanding and ability over the course of K-12 education. Content is defined to include inquiry; the traditional subject areas of physical, life, and earth and space sciences; connections between science and technology; science in personal and social perspectives; and the history and nature of science. Chapter 7 contains the program standards which provide criteria for judging the quality of school and district science programs. The system standards in Chapter 8 consist of criteria for judging the performance of components of the science education system beyond the school and district: the people and entities, including education professionals and the broader community that supports the schools. Throughout the Standards, examples have been supplied that are based on actual practice and include a brief description of some of its features and a list of the standards that might be highlighted by the example. (JRH)