Is small always better in education?

According to a NYTimes article, Brockton High School has been successful in a school-wide effort to improve performance in a school that originally had only a quarter of students passing state-wide exams and 1 in 3 students dropping out. This year, with Brockton surpassing 90% of Massachusetts high schools in state educational tests, many are looking to learn more from a school whose large scale success seems to be an exception to the opinion that smaller is better.