Last week, I blogged about the fact that Chicago students’ NAEP test score gains were modest under Arne Duncan’s leadership, and statistically indistinguishable from the modest gains made in urban districts around the nation. My analysis — which contradicts the rosy impression given by Illinois’ ISAT test — has just been released here.

Secretary Duncan has said that state and district officials should not make inflated claims about student achievement based on misleading state test scores, and has used the NAEP to fact check their claims. He’s right about that.