<P> It is logically fallacious because the mere fact that a belief is widely held does not necessarily guarantee that the belief is correct; if the belief of any individual can be wrong, then the belief held by multiple persons can also be wrong . The argument that because 75% of people polled think the answer is A implies that the answer is A fails, because, if opinion did determine truth, then there would be no way to deal with the discrepancy between the 75% of the sample population that believe the answer is A and 25% who are of the opinion that the answer is not A. However small a percentage of those polled give an answer other than A, this discrepancy by definition disproves any guarantee of the correctness of the majority . In addition, this would be true even if the answer given by those polled were unanimous, as the sample size may be insufficient, or some fact may be unknown to those polled that, if known, would result in a different distribution of answers . </P> <P> This fallacy is similar in structure to certain other fallacies that involve a confusion between the justification of a belief and its widespread acceptance by a given group of people . When an argument uses the appeal to the beliefs of a group of supposed experts, it takes on the form of an appeal to authority; if the appeal is to the beliefs of a group of respected elders or the members of one's community over a long period of time, then it takes on the form of an appeal to tradition . </P> <P> One who commits this fallacy may assume that individuals commonly analyze and edit their beliefs and behaviors . This is often not the case . (See conformity .) </P> <P> The argumentum ad populum can be a valid argument in inductive logic; for example, a poll of a sizeable population may find that 100% prefer a certain brand of product over another . A cogent (strong) argument can then be made that the next person to be considered will also very likely prefer that brand (but not always 100% since they could be exceptions), and the poll is valid evidence of that claim . However, it is unsuitable as an argument for deductive reasoning as proof, for instance to say that the poll proves that the preferred brand is superior to the competition in its composition or that everyone prefers that brand to the other . </P>

It as common as something that nobody knows