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 bact

In this argument, the author suggests that all hand-washing stations throughout their hospital system apply hand soap made by UltraClean. This claim is based on a laboratory study that indicates a distinctive reduction in harmful bacteria after using UltraClean hand soap and a recent test of regular-strength UltraClean with hospital staffs which reports fewer cases of patient infection. Whereas, lacking in convincing evidence, the validity of this argument seems unwarranted.

As is mentioned by the author, in the controlled laboratory study, a concentrated solution of extra strength UltraClean hand soap reduces greater percent of harmful bacteria and it implies the effectiveness of UltraClean hand soap. He is apparently confident in the precision of the study. The design of this controlled experiment, however, is flawed for its failure of controlling single variable. Liquid hand soaps are commonly used with non-concentrated solution of regular strength. Compared with it, we can hardly identify the decisive factor, or perhaps the concentration, strength and type of hand soap all contribute to the obvious difference. Accordingly, more restricted experiments are required to guarantee the reliability of the author’s claim.

Apart from the controlled laboratory study, a recent test of UltraClean at the author’s hospital which reports fewer cases of patient infection tend to enhance the effectiveness of the UltraClean hand soap. The comparability of their hospital is premised, yet there is no denying that less patient infection is caused by the better sanitary condition, stronger responsibility of doctors or more reasonable administration rather than the use of the UltraClean hand soap. In this case, the author should offer more details concerning the conditions of the investigated hospitals in each aspect in order to ensure that they are comparable.

Even if these study demonstrate the capability of UltraClean hand soap in reducing infection or harmful bacteria growth, the author should not rush to the assertion that it ought to be supplied to all hand-washing stations in their hospital system. He clearly assumes that the practicality of this product will not be impaired if applied to the whole hospital system. Nonetheless, the diversity of these hospitals can hardly be neglected. For instance, some hospitals own more advanced ways of sterilization so that the use of UltraClean hand soap seems totally extra. Thus more tests are needed to ensure the necessity and effectiveness of promoting this product.

Conclusively, the author attempts to advise supplying UltraClean hand soap in all hand-washing stations throughout their hospital system. Nevertheless, failing to present enough cogent evidence, the reliability of his assertion is unfounded.