“At some schools, online courses — originally intended for nontraditional students living far from campus — have proved surprisingly popular with on-campus students. At least 2.3 million people took some kind of online course in 2004, and two-thirds of colleges offering ‘face-to-face’ courses also offer online ones. But what were once two distinct types of classes are looking more and more alike — and often dipping into the same pool of students.”