In America's Lab Report: Investigations in High School Science, a National Research Council (NRC) committee found that labs have the potential to help students master science subject matter, develop scientific reasoning skills, increase interest in science, and achieve other important science learning goals. High school graduates who attain these goals are more likely to lead productive and healthy lives in their increasingly complex, high-tech society. At the same time, attaining these goals is critical in preparing the next generation of scientists and engineers. Unfortunately, the report reveals that these goals are not being achieved today. The NRC committee identified four principles of instructional design that can enhance the effectiveness of labs: (1) design science labs with clear learning outcomes in mind; (2) thoughtfully sequence lab experiences into the flow of science instruction; (3) integrate learning science content with learning about the processes of science; and (4) incorporate ongoing student reflection and discussion. (Contains 1 Editor's note.)