Logical reasoning PrepTest 121 · Section 4 · Question 4

Incorrect. First, the conclusion is that someone won't agree with the opinion of an expert. Second, this argument relies on an attack on the person flaw ("He's a criminal, so we shouldn't listen to him!"), and that flaw isn't present in the stimulus.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Flawed Parallel Reasoning

Stimulus Summary:
Most physicians I asked believe in astrology, so there must be some truth to it.

Answer Anticipation:
There are two elements in this stimulus that suggest specific flaws.

The first is that the author of this argument brings up a personal sample—physicians that "I" have talked to. That's not necessarily a representative sample, and almost anytime the sample is one that is from personal experience, it's too limited to draw the conclusion.

The second is that the argument relies on the opinion of experts. When that's the case, it's important to ensure that the "experts" are speaking to their area of expertise. Here, they're not. Physicians have expertise over medicine, not astrology or paranormal phenomena. The argument is relying on the wrong experts.

Let's find an answer with an argument relying on a personal sample of experts not shown to have expertise on the subject in question.

Answer Explanation:
This argument relies on a personal sample ("I have discussed this with") of experts whose expertise isn't applicable to the situation (biology professors talking about government spending on social programs). Both flaws from the stimulus are present in this answer, so it's correct.

Key Takeaway:
Knowing common elements that lead to specific flaws can make it a lot easier to spot flaws in arguments. This can be particularly important when there's more than one flaw in the argument so that you don't miss one (we saw here answers that had one of the present flaws but not the other), but that means you have to be vigilant at exploring all such elements and the associated flaws.

Incorrect. The sample here is of all physicists (with most agreeing with quantum mechanics), and it's also not noted as being a personal sample, so this answer is missing both flaws from the stimulus.

Incorrect. This answer has the personal sample issue from the stimulus, but it lacks the second. While it does discuss diet with mechanical engineers, it doesn't rely on their opinion to conclude the truth of a statement—in other words, it doesn't conclude that avoiding meat is healthier. It instead uses the views of a group to draw an inference about their behavior—that's flawed, but not flawed because of an inappropriate appeal to experts. Rather, it's assuming that people act in a manner that aligns with their beliefs, which is a different flaw.

Incorrect. This argument doesn't use a personal sample, and that sample isn't put out as experts at anything. It also jumps from UFOs to aliens, which is a separate jump not present in the stimulus.