Peter Greene wants to warn readers about a new study of Rocketship charter schools that he finds not credible. Maybe it is because the Rocketship corporation always relies on the same evaluators to do their studies, and he suspects they have become too interdependent over the years. Maybe it is because they measure what is not easily quantified. Maybe it’s because the study will soon appear as part of a sales pitch. Whatever. He finds it bizarre to speak of “months of learning gained,” a metric that is of dubious merit. From his perspective, this is just so much edubizness hype.