The argument presented is from a director of hospitals who argues that his hospital should switch from the generic hand soap he and his staff of nurses have been using for years to a hand soap produced by his company, UltraClean. The director asserts, based on the results of his experiment, that UltraClean is more effective than the generic hand soap.

The director’s argument rests on three assumptions. Assumption number one is that UltraClean is more effective than the generic hand soap. The director is assuming that UltraClean does a better job of cleaning hands than does generic hand soap. It is not clear, however, that this assumption is true. The director does not address the possibility of bacterial resistance. If UltraClean somehow provides better cleaning than generic hand soap, then hospitals may find themselves using UltraClean for hand disinfection even though the incidence of bacteria-related infections is actually lower with generic hand soap. The director’s assertion that UltraClean produces a 40 percent reduction in bacteria may be true, but the hospital management team may want to test this hypothesis. Assumption number two is that the director’s hospital in Workby is one of eight hospitals in his group. If this assumption is false, then the director’s experiment is meaningless. If his hospital is a member of the group that encompasses all of the director’s hospitals, then the results could be significant. In that case, the director should base his recommendation on his findings only if he demonstrates that his hospital is performing at a higher level than the other seven hospitals. If this is not the case, then the director should undertake additional testing. Assumption number three is that UltraClean is more effective than the generic soap in all hospitals in the group. If the director intends to offer a blanket recommendation to all of his hospitals, then he may have gathered data that offers no benefit to any of the hospitals. In that case, he must consider each hospital individually before recommending use of UltraClean.

If the results of this experiment show that UltraClean is more effective than the generic soap, then the director should present his recommendation to the management team of each hospital. It may be true that UltraClean reduces bacteria in the hands, but the director must know if the bacteria being reduced are the kind that cause infection. If the hospital uses generic soap, then the director should test bacteria in the hands before and after a patient uses UltraClean. If the bacteria numbers decrease after the patient uses UltraClean, then the director can reasonably conclude that UltraClean is more effective than generic soap. If the numbers do not decrease, then the generic soap may be just as effective at cleaning the hands as the UltraClean soap. The hospital managers cannot know that UltraClean is more effective than generic soap unless they test both soaps. If the managers know that UltraClean is more effective than generic soap, then they will want to consider switching to UltraClean. If UltraClean is less effective than generic soap, then the managers may want to keep using the generic soap. The manager may want to consider testing UltraClean in one or two of the hospitals in the group before recommending that it be used in all of the hospitals.

The director may believe that the generic hand soap is less effective than the UltraClean soap. In that case, the director needs to present evidence that his hospital is an exception. The director should test bacteria in the hands before and after patients use UltraClean. If the numbers are higher after a patient uses UltraClean, then the director can conclude that UltraClean is more effective than the generic soap. If the numbers are not higher with the UltraClean soap, then the director should not recommend UltraClean as hand soap for his hospital. Assumptions about the superiority of one product over another do not follow from the results of one test performed at one hospital. The hospital management team must test the soap before it can make an informed decision about which soap to use.