By all accounts the statistics-heavy new system--a "growth percentile model" by which students are compared with peers who scored similarly on the previous year's test--is hard to wrap your head around. One thing is certain though: it will reduce the number of schools getting A's and B's. "We want to be able to really show how much value a school is actually adding," said Shael Polakow-Suransky, the department's chief accountability officer.">Sabrina Jaszi: