The seed for this study was germinating in the Commission on Life Sciences of the National Research Council when the Board on Biology was created in 1984. The board's attention was initially drawn to high-school biology by the controversy over the inclusion of evolution in the school curriculum, but in a one-day workshop with teachers and textbook publishers it quickly became apparent that myriad other problems beset the teaching of science. As the present study got under way, it was our intention to focus on the high-school biology curriculum, but we found that restricted goal elusive. Perhaps I can explain why by paraphrasing one of our reviewers, who characterized this report as describing the "ecology" of science education. That puts it well, for this is a report about complex relationships—how failure of learning in high-school science has its origins in elementary school, how texts, tests, teacher education, colleges and universities, and political and economic assumptions all contribute to the status quo, and how difficult it is to alter any one element alone and expect any meaningful change in the entire system. There is of course a history, too — how the nation's educational system got into its present state, and why previous efforts at reform of science education have been so ephemeral. In short, as our deliberations progressed, we were compelled by the nature of the problem to broaden the scope of our analysis.