THIS chart shows what the school system "wants"
PLUS a "special" or "outside" cause of variation, parent education.
NOT what school board members want.
NOT what superintendents want.
-- no performance data available --Chatom Union
Students would perform better the more years in school IF the follow-the-schedule method wanted that.
But that's not what it "wants"...and it's not a coincidence this pattern repeats (repeatedly).