GreatSchools Ratings for Virginia are based on the 2007-2008 Standards of Learning (SOL) End-of-Grade reading, writing, math, science and history/social science results and the End-of-Course reading, writing, algebra I, algebra II, geometry, biology, chemistry, earth science, world geography, Virginia and United States history, world history I and world history II results. Grade 8 history/social science results were not included due to incomplete reporting by the state. GreatSchools compared the test results for each grade and subject across all Virginia schools and divided them into 1 through 10 ratings (10 is the best). Please note, private schools are not required to release test results, so ratings are available only for public schools. GreatSchools Ratings cannot be compared across states, because of differences in the states' standardized testing programs. 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.