In his 2010 annual letter for the Bill & Melinda Gates Foundation, Bill Gates suggested that have at least one great course online for each subject rather than lots of mediocre courses. The idea is that students could freely access these "best possible" lectures online - which might in turn replace more mediocre real-life lectures.
Several top universities already offer some of their lectures online for free, including the Open Learning Initiative at Carnegie Mellon University, M.I.T.’s OpenCourseWare program, Columbia, Harvard, Yale, Stanford, and the University of California, Berkeley. The UK-based OpenUniversity offers free online courses. Aggregator website Academic Earth offers a collection of over 150 full courses from different universities. Additionally, youtube edu offers a collection of lectures.
However, could such online lectures truly replace traditional education? There are several issues to hinder online courses to replace human-taught courses. First, online courses are notorious for high dropout rates. Personal relationships with instructors and other students might help students persevere. Second, many universities may now offer online lectures but complete courses consists of more than just the lecture, for example discussion groups, feedback from instructors, study groups, and office hours. These elements are currently missing in free online courses. Third, while lectures might be freely available, universities do not give credit for studying them. Free online courses do not (yet) lead to academic degrees. A step in this direction was taken last year by the regents of the University of California when they approved a proposal to test the viability of offering a bachelor’s degree that could be earned entirely online.
Read more in this New York Times article: Online Courses, Still Lacking That Third Dimension - NYTimes.com