The FDA requires drug companies and device manufacturers to show “proof of concept” before moving on to human clinical trials. Notably, this “preclinical research” largely occurs in the lab, where researchers use tightly controlled experiments to evaluate mechanisms of action and potential for toxicity. This is not how it works in education. A “proof of concept test” in education would require interventions to be rooted in what we know about how teaching produces learning. The body of work is housed in the developmental and cognitive sciences, education’s closest approximation to medicine’s laboratory. But these fields are largely peripheral to the work in education and do not feature prominently in the field’s leading journals or in the grantmaking activities of IES.