When former students run into Jay Humbard, they tell him that they still remember his crazy tests from a non-calculus physics class he taught at a state university two decades ago. In fact, he was something of a legend in the Greek organizations for years, as students revisited his old exams on file. Now CEO of Control Vision Corp., he recalls one of his favorite test problems with particular relish. "I set it up so that the answer to the first question was the number one, the second question the number two, and the third question the number three," he says. "The fourth question, though, was correctly answered as 62 and some change, while the fifth and final answer was five." He is still awed by the number of students who managed to get the answer "four" out of the fourth question, even going so far as to show the work that led to that conclusion. "Practically all of the students reworked the problem at least once, many happily convincing themselves that I was just a sadistic SOB and that they could be confident in their answer," says Humbard. The point, he says, was of course to see just how sure of their work they were.