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 of using broadcast media to teach by examining a century of efforts to use it at home and in the classroom. Along the way, he shares stories from teachers, administrators, entrepreneurs, and innovators who promoted the use of cutting-edge technology-while critically evaluating their motives for doing so. Taking a close look at the origins of various media forms, their interrelatedness, and their impact on education thus far, Ferster asks why broadcast media has been so much more successful at entertaining people than it has been at educating them. Accessibly written and full of explanatory art, Sage on the Screen offers fresh insight into the current and future uses of instructional technology, from K-12 through non-institutionally-based learning.