Since the days of Thomas Edison, technology has held the promise of lowering the cost of education. The fantasy of leveraging a fixed production cost to reach an unlimited number of consumers is an enticing economic proposition, one that has been repeatedly attempted with each new media format, from radio and television to MOOCs, where star academics make online video lectures available to millions of students at little cost.

In Sage on the Screen, Bill Ferster explores the historical, theoretical, and practical perspectives ofusing broadcast media to teach by examining a...