When Nog applied to the Academy in 2371, Chief O'Brien proctored his stress reaction test in one of Quark's holosuites. Nog studied hard and was prepared for the test, but he erroneously believed it would be a test on his performance as pilot of a runabout. The actual test put Nog in Deep Space 9's operations center; O'Brien had intentionally led Nog to believe otherwise, as this made it a truly stressful test rather than routine review of something Nog knew well.