Encore: What a Forgotten Instructional Fad From the ‘70s Reveals About Teaching

In the 1960s and '70s, an experimental form of teaching made a big splash at colleges. It was called PSI, or the Personalized System of Instruction. And it's largely forgotten, says Jonathan Zimmerman, a professor at the University of Pennsylvania, author of a new book on the history of college teaching in America. Here's what today's colleges can learn from the fad.