A club wanted to determine whether it could increase attendance by changing its weekly meetings from Tuesday to another day. At one Tuesday meeting, the club's president took a survey of all members present. Of those surveyed, 95 percent said that they had no difficulty attending on Tuesdays. On the basis of this survey result, the club's president concluded that the attendance problem was not due primarily to schedule conflicts.
A questionable technique used in the club president's reasoning isThe president surveyed only the members who were present at a Tuesday meeting. But members who have trouble attending on Tuesdays are exactly the people likely to be absent from a Tuesday meeting.
So the sample is likely biased and does not represent the whole club, especially the members whose attendance is the problem.
(A) drawing a conclusion on the basis of circular reasoning
This is not the flaw. The president does not simply assume the conclusion. The problem is the
unrepresentative sample.
(B) making a generalization on the basis of a sample that is likely to be unrepresentative
This is correct. The president generalizes from people who attended on Tuesday to the whole club. But people absent from Tuesday meetings may be absent because Tuesday is inconvenient.
(C) treating a generalization that applies to most cases as if it applied without exception
This is not the issue. The president is not applying a general rule too broadly; the president is using a biased survey sample.
(D) drawing a conclusion on the basis of premises that contradict one another
This is incorrect. The premises do not contradict each other.
(E) inferring, solely from the claim that a change is not sufficient to solve a problem, that it is not necessary either
This is not happening. The president is not discussing sufficient versus necessary conditions. The problem is that the survey missed many relevant people.
Answer: (B)