17. This ad recommends non-prescription1 Acid-Ease over non-prescription Pepticaid
for relief of excess stomach acid. The only reason offered is that doctors have written 76
million more prescriptions2 for the full-strength prescription form of Acid-Ease than for
full-strength Pepticaid. While this reason is relevant, and provides some grounds for
preferring Acid-Ease over Pepticaid, it is insufficient3 as it stands because it depends on
three unwarranted assumptions.
The first assumption is that the prescription form of Acid-Ease is more popular
among doctors. But this might not be the case, even though doctors have written 76
million more prescriptions for Acid-Ease. Acid-Ease may have been available for
several more years than Pepticaid; and in the years when both products were available,
Pepticaid might have actually been prescribed more often than Acid-Ease.
The second assumption is that doctors prefer the prescription form of Acid-Ease
for the reason that it is in fact more effective at relieving excess stomach acid. However,
doctors may have preferred Acid-Ease for reasons other than its effectiveness. Perhaps
Acid-Ease is produced by a larger, more familiar drug company or by one that
distributes more free samples. For that matter, the medical community may have simply
been mistaken in thinking that Acid-Ease was more effective. In short, the number of
prescriptions by itself is not conclusive4 as to whether one product is actually better than
another.
The third assumption is that the milder non-prescription forms of Acid-Ease and
Pepticaid will be analogous5 to the full-strength prescription forms of each. But this
might not be the case. Suppose for the moment that the greater effectiveness of
prescription Acid-Ease has been established; even so, the non-prescription form might
not measure up to non-prescription Pepticaid. This fact must be established
independently.
In conclusion, this ad does not provide enough support for its recommending non-
prescription Acid-Ease over non-prescription Pepticaid. To strengthen its argument, the
promoter of Acid-Ease would have to show that the comparison between the number
of prescriptions is based on the same time period; its effectiveness is the main reason
more doctors have prescribed it, and the comparative effectiveness of the two non-
prescription forms is analogous to that of the prescription forms
相关文章推荐
