The SchoolGrades numeric score answers this question: if MILL VALLEY MIDDLE served the average American student population, what percentage of students would meet rigorous national standards in reading and math? The answer is 62 percent.
1 Apply a Rigorous National Standard
We begin by looking at the percentage of students who earn scores that qualify as proficient on state math and reading exams. We average the proficiency rates in these two subjects to get the school's overall state proficiency percentage.
Given that it's often easier to earn a proficient score on a state exam than on a leading national exam (i.e., NAEP), we then determine the percentage of students who meet the more rigorous national standard. This allows us to compare how the school's students are doing relative to their peers across the country.
While 38 percent of students in California qualify as proficient under the state's own standard, 33 percent of the state's students qualify as proficient under rigorous national standard (i.e., NAEP). We use this difference to apply the rigorous national standard to the school's test results.
2 Adjust for the Students' Economic Profile
We then take into account the percentage of students who qualify for the federal government's free and reduced price lunch program. This adjustment gives extra credit to schools that serve economically disadvantaged students and holds schools that serve affluent students to a higher standard.
3 Assign the Final Letter Grade
The last step in our process is to assign final letter grades - A, B, C, D, F- based on how the school would rank internationally in comparison to the performance of students in more than 60 countries on the Program for International Student Assessment (PISA) exam.
MILL VALLEY MIDDLE's overall adjusted proficiency rate of 62 percent earns it a grade of A. The school's performance is similar to the average performance of schools in Singapore, South Korea, Japan, Switzerland. 27% of American schools receive a grade of A.