On Saturday, when 600,000 high school students open their SAT test booklets, one question they won't find is: Why are they required to complete this key college admissions exam within three hours? The correct answer: Because the tests always have been strictly timed. Yet the College Board, which administers the test, concedes the time limit isn't intended to measure how students perform under deadline. Rather the restriction merely serves a logistical purpose. Providing more time would complicate efforts to book rooms and protect against cheating. Because the College Board is wedded to a stopwatch system, it places unnecessary time pressures...