Before providing a sample of the results at the four schools (A-D), we address two important issues that affect their interpretation: school/teacher differences and obtaining consent. First, the student populations and curricula differ substantially across the schools so it is difficult to combine inter-school data. There were also some differences between the control and treatment groups within a single school, despite comparing the same course. For example, at school D the CPS teacher was much less experienced at teaching physics than the control teacher. In addition, there were some issues that arose in conjunction with the assessment administration process. In two of the four schools (C and D), teachers of the control classes were reluctant to spend class time on the assessments. As an alternative a shorter out-of-class assessment was scheduled but, because it was voluntary, lost the clean interpretation of having all the students included. Since at these schools only three of the five tests were administered, we have different amounts of data from different schools. Secondly, in some schools the return rate for parental consent and student assent forms was low. The four schools are described below with a brief summary of the test results at each school. For mean score differences that are statistically significant, the p-values are provided in parentheses.