So how did we choose the best high schools on this honor roll? The Academic Performance Index (API) scores range from 200 to 1000 and are calculated from the results for each school’s students on statewide tests. Public schools in Los Angeles County were considered for this analysis if their 2006-7 API score was at least 800, the median of a basic score (725) and a proficient one (875) and the state’s performance goal for all schools. In addition, schools had to meet minimum standards: an enrollment of 200 students for all schools, a graduating class of 50 students for public schools, and a graduating class of 65 students for private schools. Schools were excluded if they declined to participate or if data were not available. Our index is based on a weighted average of scores assigned to five variables: API score, student-teacher ratio, percentage of students going to college, dropout rate, and advanced placement ratio (this ratio represents the number of AP sections offered, divided by the number of graduates). Private schools had to meet similar standards to avoid exclusion; their index is based on a weighted average of scores assigned to a slightly different set of variables, including the average SAT score for students enrolled at the school. The SAT is scored on a scale of 200 to 800 in each of three sections–writing, mathematics, and critical reading–allowing for a total possible score of 2400. SAT scores were used in evaluating private schools but not public schools. Scores for API testing (taken by public school students only) are considered a more accurate form of measuring students’ academic abilities. If a school was missing only its SAT result, the number was projected through a technique known as imputation.