More schools in the United States have begun teaching physics to ninth-graders, but there continues to be limited evidence that such a change benefits students. Many arguments in favor of Physics First and the inverted sequence of physics-chemistry-biology are based more on the intellectual logic of the sequence than on measured outcomes. Paul…

This study examined science textbooks over time to better understand the "science content" expectations that the U.S. educational system deems appropriate for 8th and 9th grade science students. The study attempted to answer the questions: (1) What specific science content has been presented via the textbook from 1952 to 2008? (2) Within…