During the course of the 20th century, educational research yielded to the lure of Galileo’s vision of a universe that could be measured in numbers. This was especially true in the United States, where quantification had long enjoyed a prominent place in public policy and professional discourse. But the process of reframing reality in countable terms began eight centuries earlier in Western Europe, where it transformed everything from navigation to painting, then arrived fully formed on the shores of the New World, where it shaped the late-blooming field of scholarship in education. Like converts everywhere, the new American quantifiers in education became more Catholic than the pope, quickly developing a zeal for measurement that outdid the astronomers and mathematicians that preceded them. The consequences for both education and educational research have been deep and devastating.