Logical reasoning PrepTest 132 · Section 2 · Question 16

Incorrect. Relying on self-reported data to establish factual information weakens a study.

Incorrect. The reason for undergoing throat surgery doesn't speak to the cause of those abnormalities. If anything, the argument potentially raises an alternative—the surgery caused the abnormalities (note that this doesn't state that the biopsies were taken during surgery).

Incorrect. This answer establishes that the individuals in the study were comparable along a number of metrics, but these metrics aren't known to be related to throat abnormalities.

Incorrect. This answer deals with the relationship between throat surgery and snoring, not throat abnormalities and snoring.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen

Stimulus Summary:
Sample – Those who underwent throat surgery
Correlation – Frequent snoring and throat muscle abnormality
Conclusion – Snoring damages the throat

Answer Anticipation:
This argument is about a study done on those who underwent throat surgery. Whenever there's a study, we should look at a potential sampling flaw, and a correlation/causation flaw.

Starting with the sampling flaw, the argument does start with those who have undergone throat surgery, so that group isn't necessarily representative of the general public. However, the conclusion isn't about the general public—it's a weak causal statement, just that snoring can cause throat damage. Even if that only exists within this subset of the population, it's still a valid argument, so there's no sampling flaw here.

Next, we need to consider a potential correlation/causation flaw. The premise here notes that people with one characteristic are "significantly more likely" to have another characteristic. That's correlative language, and the conclusion is causal ("damage"), so there is a correlation/causation flaw. The correct answer, therefore, will fall into one of our common patterns for Strengthen questions with this flaw:

(1) Eliminate an alternative cause
(2) More examples of cause and effect together
(3) Control group—a group without the cause and without the effect
(4) An explanation of the causality

Answer Explanation:
The argument concludes that snoring damages throat muscles. This answer choice rules out an alternative possibility—that the causality flows in the reverse direction. In ruling out reversed causality, this answer strengthens the argument.

Key Takeaway:
The two most common flaws in arguments based on a study (or survey/poll) are sampling and correlation/causation. Start by looking for those and you'll hit gold most of the time!