The following appeared in a memo from the director of a large group of hospitals.
"In a controlled laboratory study of liquid hand soaps, a concentrated solution of extra strength UltraClean hand soap produced a 40 percent greater reduction in harmful bacteria than did the liquid hand soaps currently used in our hospitals. During our recent test of regular-strength UltraClean with doctors, nurses, and visitors at our hospital in Worktown, the hospital reported significantly fewer cases of patient infection (a 20 percent reduction) than did any of the other hospitals in our group. Therefore, to prevent serious patient infections, we should supply UltraClean at all hand-washing stations, including those used by visitors, throughout our hospital system."
Write a response in which you examine the stated and/or unstated assumptions of the argument. Be sure to explain how the argument depends on these assumptions and what the implications are for the argument if the assumptions prove unwarranted.
In this memo, the author attributes the 20 percent reduction in patient infections to UltraClean soap, and while this explanation may seem plausible, additional explanations could lead to the same phenomenon.
First, the author compares the results of the hospital in Worktown study to other hospitals in the group and shows that hospitals using UltraClean soap had a twenty percent reduction in patient infections compared to other hospitals. While this may be due to the use of UltraClean soap, there are other differences between hospitals that need to be considered. For example, the level of disinfection and management differs from hospital to hospital. It is very likely that hospitals in Worktown disinfect more frequently than other hospitals, or have stricter oversight of doctors and nurses and visitors, with everyone entering and leaving the hospital going through stringent disinfection measures, compared to other hospitals that have weaker management levels and disinfection strictness. These circumstances would cause hospitals in Patients in Worktown to be less likely to be infected with germs.
Secondly, we should also compare the situation of patients in different hospitals. It is possible that the hospital in Worktown does not admit patients with infectious diseases. For example, the hospital is actually an eye hospital or a dental hospital, so people are less likely to contract the disease at the hospital in Worktown. In contrast, the other hospitals in the group are all infectious disease hospitals, and patients would have had a higher rate of infection in those hospitals. Similarly, differences between the immunity of patients in different hospitals can also lead to differences in the probability of infection mentioned in the text. For example, patients in the hospital in Worktown are inherently more immune, while patients in other hospitals are less resistant, leading to a lower probability of infection in patients in the hospital in Worktown.
Finally, in addition to the use of UltraClean soap, we must also consider the other disinfectant measures and products used at the hospital in Worktown that lead to a lower infection rate. For example, the hospital in Worktown uses UltraClean along with other disinfectant water, disinfectant soap, etc., and it is possible that these other disinfectant products are the real reason for the lower infection rate.
All in all, the phenomenon mentioned in the memo is such a case that it requires more considerations of alternative explanations that could account for the facts presented in the article.