In calculating these ratings, GreatSchools analyzed the 2011-2012 Michigan Educational Assessment Program (MEAP) and the Michigan Merit Examination (MME) results and compared them to all Michigan schools with the same grade levels.
If there are no GreatSchools Ratings for a school, the school's test results were either not reported or incomplete.
Keep in mind that when comparing schools using GreatSchools Ratings, it's important to factor in other information, including the quality of each school's teachers, the school culture, special programs, etc.
GreatSchools Ratings cannot be compared across states, because of differences in the states' standardized testing programs.