In the 1990s, the K-12 subject matter communities, comprised of education researchers, curriculum developers, scientists, teacher educators, and teachers, developed frameworks to guide state and local authorities with curriculum development. These became the National Science Education Standards (NSES)1 and the Benchmarks for Science Literacy.2 In turn, local and state authorities developed standards, curricula, and assessments that were meant to align with the national standards.
The development of standards and benchmarks was an important step toward building and expressing shared values for K-12 science education. These standards succeeded in building common frameworks. While standards were marginally rooted in research on children’s learning and analyses of scientific practice, we now have a richer research base to inform science education and a better sense of the critical role this research should play.
Current national, state, and district standards do not provide an adequate basis for designing effective curriculum sequences, for several reasons. First, they contain too many topics. When the NSES were compared with curricula in countries that participated in the Third International Mathematics and Science Study, the NSES were found to call for much broader coverage of topics than those in high-achieving countries.3
Second, the NSES and benchmarks do not identify the most important topics in science learning. Comparisons of the NSES with curricula in other countries show that they provide comparatively little guidance for sequencing across grades. As we pursue a course of organizing curricula around core ideas, we need to ask ourselves questions that were not central to the development of the current standards. What areas of study are critical for students’ future learning? Which of these critical areas of scientific study can students explore in meaningful and increasingly complex ways across the K-8 grade span and beyond? Which areas of science can safely be deferred until high school or college? These are not easy questions, and answering them will require collective, sustained attention and focus among a number of stakeholders.
Finally, the NSES and benchmarks provide limited insight into how students’ participation in science practices can be integrated with their learning about scientific concepts; that is, they do not describe how an understanding of scientific concepts needs to be grounded in scientific practice. In addition, although the