Dr. Alex Tabarrok: "Online education can also break the artificial lecture length of 50-90 minutes. Many teaching experts say that adult attention span is 10-15 minutes in a lecture, with many suggesting that attention span has declined in the Internet era. Nevertheless, it is clear that the standard lecture length has not been determined by optimal learning time but by the high fixed costs of traveling to school. Lower the fixed costs and lectures will evolve to a more natural level, probably between 5-20 minutes of lengthperhaps not coincidentally the natural length of a lecture is probably not that different from the length of a typical popular music track or television segment." Facts About the Author of the Above Statement Dr. Alex Tabarrok is Bartley J. Madden Chair in Economics at the Mercatus Center at George Mason University and director of research for The Independent Institute. He is the co-author with Tyler Cowen of the popular economics blog Marginal Revolution and co-founder of the online educational platform Marginal Revolution University. He is the author of the recent e-book Launching the Innovation Renaissance (TED books) and Modern Principles of Economics, a leading principles of economics textbook (with Tyler Cowen). True or