June 2007 PrepTest, Section 3, Question 15
By Brandon Beaver | Published October 29, 2024
Type: Weaken
Difficulty:
Explanations
Don’t let the numbers confuse you on this one.
The argument boils down to: longer treatment is more effective than shorter treatment because the percentage of people who respond positively to the survey increases as treatment length increases.
That’s a subtle correlation-causation flaw.
The author’s saying longer treatment creates more positive patient feedback, so longer treatment must be more effective. But it’s just as likely that the patients who feel good about their therapy decide to stick with it for longer.
We have to weaken the argument, so we need to make it less likely that longer treatment is more effective.
A
This doesn’t impact the conclusion. We don’t know what proportion of the less-than-six-months group responded this way on the survey.
B
Nope. Survey response rate tells us nothing about treatment effectiveness.
C
Yes, this is it. This reverses causality—instead of longer treatment leading to better patient outcomes, the patients’ positive responses to therapy led to them continuing therapy.
D
But this would apply to both short- and long-term patients, so it tells us nothing about treatment length and effectiveness.
E
This is probably true, but it doesn’t influence patient outcomes—we have no clue whether people follow their doctor’s advice.
Passage
A consumer magazine surveyed people who had sought a psychol
Question 15
Which one of the following, if true, most seriously weakens