The following appeared in a memo from the director of a large group of hospitals."In a laboratory study of liquid antibacterial hand soaps, a concentrated solution of UltraClean produced a 40 percent greater reduction in the bacteria population than did t

The director of a large group of hospitals argues for using Ultraclean at all hand-washing stations throughout his hospital system. He supports it with help of a laboratory test and subsequent test of Ultraclean at one one of his hospitals. However, there are a number of assumptions made which need to be critically analyzed before concluding that argument is sound.

Firstly, there is assumption that greater reduction of bacterial population is enough indication of greater efficacy. It may be that ultraclean is much difficult to use than traditional liquid antibacterial soaps. The bottle that contains it may be much difficult to squeeze and thereby put off the patients from using the solution multiple number of times. This in turn means it has much less efficiency as patients are unwilling to use it. There is no evidence of ease of use of solution and thereby rendering the assumption suspect and unwarranted.

Secondly, there is the assumption that it is ultraclean which is responsible for fewer cases of patient infections in Workby as compared to other hospitals. This is misinterpreting correlation as causation. Just because Ultraclean was used during that period does not mean it alone is responsible for the improvement. There could be other reasons like the hospital would have made efforts for increasing patient awareness about proper cleaning to prevent infections and the patients may be unaware of new product and still used the old liquid antibacterial hand soaps. There is no evidence presented to preclude the other reasons and furthermore there is no evidence that patients did use Ultraclean. Without them, the assumption becomes unwarranted and the argument becomes flawed.

Thirdly, even if the above assumption is true and the Ultraclean was effective in reducing patient infections, the argument makes further assumption that this ensures its effectiveness against serious patient infections. There is no evidence presented that proves that ultraclean is effective against serious patient infections.It may be that it only useful for minor infections. Thus, the assumption becomes unwarranted. This makes argument to use it in all other hospitals for serious infections unsound.

In conclusion, there are a number of assumptions made which need more evidence in order for them to be warranted. Otherwise, the argument rests on tenuous grounds.