To create grades on the degree to which state-level measures of student proficiency aligned with national expectations of proficiency, we relied on an analysis by Paul Peterson and Peter Kaplan of Harvard University, published in the journal Education Next in fall 2013. In that study, the authors compared the percentage of students identified as proficient on the 2011 NAEP exam with the percentage of students identified proficient on the state’s own accountability exam. The larger the difference (that is, the more students were identified as proficient by the state but not by NAEP), the lower the score.
The authors of the study curved the grades differently from how the other grades in this report were curved. They gave A’s to the top 10%, B’s to the next 20%, C’s to the next 40%, D’s to the next 20%, and F’s to the bottom 10%, fitting them more closely to a bell curve. We reproduced their grades here faithfully.