When decisions are made there is a cost to making a mistake. This cost is often different for an erroneous positive decision than it is for an erroneous negative one. Decisions based on test scores are no different. We discuss this issue and provide several evocative examples. For admissions testing, two kinds of errors can be made: accepting a student who should not have been accepted (i.e., won’t graduate) and rejecting a student that would have graduated. The latter type of error likely results in very few actual errors as the student can simply enroll elsewhere. But the former type of error can result in time and money wasted. The proper use of test scores reduces both types of errors. For licensing tests, passing someone who should not have been passed can have more serious consequences than time and money. An airline pilot’s lack of knowledge and skills can lead to a crash; a doctor’s inadequacies and incompetence can lead to deaths. Using test scores can save lives.