The recruitment and training of the next generation of scientists depends critically on the success of K-12 and undergraduate education. The symposium exemplifies recent work by research psychologists to strengthen evidence-based approaches to science education. The particular focus is on directly teaching principles of scientific inquiry and reasoning. Science education necessarily emphasizes domain-specific knowledge; but to varying degrees, science education also attempts to instruct students on the general principles of scientific thinking. The symposium presents efforts to develop new approaches and tools to teach scientific principles and to deepen students’ understanding of them. Recent work by cognitive psychologists has examined how scientists reason, both experimentally and in the natural setting of the research laboratory. This empirical research can inform the content of what students are taught about successful scientific research strategies. New research to develop computer-based methods aims to provide tools to teach students principles of scientific reasoning as a supplement to traditional science courses. One of the two studies includes an evaluation of its effect on low-socioeconomic status middle-school students. Together, this research offers the prospect of deepening students’ understanding of science and its interconnectedness across fields of study.