AAAS Science Assessment Website – Science educators have easy access to more than 700 high-quality multiple choice items for testing middle and high school students' understanding of 16 important topics in earth, life, and physical science and the nature of science. The website also presents data on the state of science learning by gender and whether or not English is the student’s primary language. An online testing feature lets users select items, assemble them into tests, and administer and score the tests online. Development of the items and the website was made possible by a grant from the National Science Foundation. Contact: George Deboer, Principal Investigator, contact George