Peter Greene knows, unlike Bill Gates, that children are not like toasters that Ned to be plugged into an electrical outlet that is everywhere the same. But then Gates brings in the metaphor of a railroad gauge. Ah! A fresh metaphor! New writer? Who knows?

Greene explains why it is a bad metaphor that has nothing to do with students or teaching. And he asks the $64 question: if standardization and uniformity are so great, why does Gates love charter schools?

And now the big question: what metaphor will Gates use next to make the case for standardization of learning?