PrepTest 149, Section 1, Question 4
A survey published in a leading medical journal(47 more words not shown)
The reasoning above is questionable(3 more words not shown)
- Aignores anecdotal evidence(8 more words not shown)
- Bconsiders only surveys(6 more words not shown)
- Cconcludes merely from(12 more words not shown)
- Dpresumes, without providing(13 more words not shown)
- Efails to consider(13 more words not shown)
Reading the argument
What else comes with exercising regularly? Maybe these people eat differently. Maybe they're less likely to smoke. Either difference could help explain why they have less lung disease without exercise itself being the cause of the lower risk.
The repeated surveys make the pattern more convincing: frequent exercise and lower lung-disease risk tend to go together. But repeating a pattern doesn't tell us why it occurs. If the people who exercise also differ in other ways, every survey could find the same association without isolating the effect of exercise.
What we’re looking for
That's the flaw to look for. The author moves from two things appearing together to a claim that one produces the other. We can accept the survey results while questioning that explanation.
Working the answers
- A
No anecdotal evidence is presented and then ignored. More importantly, relying on research instead of personal stories isn't inherently a mistake. The issue is what these surveys establish, not that the author should have preferred anecdotes.
- B
We're told where the first survey was published, but not where the other surveys appeared. Even if all were in one journal, that fact alone wouldn't identify the problem. Several surveys can confirm an association without showing that exercise caused the health difference.
- CCorrect
Exercise frequency and lower lung-disease risk are correlated: they tend to vary together. The author treats that relationship as proof that exercise benefits health. But another difference, such as smoking habits, could account for the lower risk. The surveys as described don't establish which explanation is right.
- D
A benefit to health doesn't require perfect health. Someone could have a lower risk of lung disease while still having another serious illness. The author doesn't need to assume everyone without lung disease is healthy in every other respect.
- E
Infrequent exercise could have a small benefit and frequent exercise a larger one. That would fit the author's view rather than expose its mistake. The problem is establishing that exercise produces the benefit at all, not deciding that only frequent exercise could ever help.
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