Here are the 2009 "student growth percentiles" for school districts statewide, released Oct. 27th by the state Department of Elementary and Secondary Education. The new statistics report the performance of a student or groups of students as they progress from one grade to the next -- allowing schools and parents to see how much or how little educational growth has occurred over time. The figures are one way of measuring the effectiveness of schools and school districts.

The new system analyzes three years worth of MCAS data. Students are put in peer groups based on their performance on the 2007 and 2008 MCAS English and mathematics exams. Their 2009 scores are then compared to others in this peer group, and ranked by percentile. For example, students who scored in the 65th percentile did better on the 2009 MCAS exams than 65 percent of students statewide with the same academic history. The scores shown below for school districts represent the median growth percentile of its individual students. The median score statewide was 50%.

The state did not calculate a growth percentile for districts with fewer than 20 students, and warns that differences in percentiles of less than 10 points are not likely to be educationally meaningful.