Here is how the site describes itself:
Here you will find free access to more than 600 items. The items:
- Are appropriate for middle and early high school students.
- Test student understanding in the earth, life, physical sciences, and the nature of science.
- Test for common misconceptions as well as correct ideas.
This website also includes:
- Data on how well U.S. students are doing in science and where they are having difficulties, broken out by gender, English language learner status, and whether the students are in middle school or high school.
- “My Item Bank,” a feature that allows you to select, save, and print items and answer keys.