NPR Ed HOW LEARNING HAPPENS

MIT is one of several schools that offer classes through edX, which provides free online courses in partnership with some of the country's top universities. Joe Raedle/Getty Images hide caption

itoggle caption Joe Raedle/Getty Images

Ruth Hálová, a survivor of the Holocaust (clockwise): Ruth as a child dressed up for a play; Ruth's 1st grade class taken in 1932; Ruth and husband Milan Hala in India in the 1990's; Ruth and her mother in (the then) Czechoslovakia after the war. Centropa Photo Archives hide caption

itoggle caption Centropa Photo Archives

Jorge Cham is the creator of PHD Comics and received his doctorate in mechanical engineering at Stanford University. PHD (Piled Higher and Deeper) is a comic strip about life (or the lack thereof) in academia. See more of his work at www.phdcomics.com. Jorge Cham/PHD Comics hide caption

itoggle caption Jorge Cham/PHD Comics

John Scarborough, a fourth-year pharmacy student at Lipscomb University, talks to high schoolers during a vocational career training class. Courtesy of Lipscomb University hide caption

itoggle caption Courtesy of Lipscomb University

Hugo Villavicencio talks to kindergarten students at Lenicia B. Weemes Elementary School about the importance of attending school. Benjamin Brayfield/Southern California Public Radio/KPCC hide caption

itoggle caption Benjamin Brayfield/Southern California Public Radio/KPCC

For his study Professor Benjamin Schmidt culled roughly 14 million reviews from the website Rate My Professor. Blue dots represent male professors, red dots female. The farther right the dot, the more often that the word on the left was used to describe the professor. Alyson Hurt hide caption

itoggle caption Alyson Hurt