States have previously used the National Science Education Standards from the National Research Council (NRC) and Benchmarks for Science Literacy from the American Association for the Advancement of Science (AAAS) to guide the development of their current state science standards. While these two documents have proven to be both durable and of high quality, they are around 15 years old. In addition, major advances have since taken place in the world of science and in our understanding of how students learn science effectively. Explore the timeline below to read some of the recent foundational science education research and reports on which the Next Generation Science Standards were based.