PT158 S4 Q18 ExplanationLindsey: Several people claim that

Answer choices, explained

1. A

   Bad Evidence Match14% picked this

   relies on the opinions of certain unnamed people without establishing that those people were well

   This answer describes a flaw involving reliance on unnamed or poorly informed authorities. But Lindsey does not rely on unnamed sources to build her OWN case — she responds to other people's complaint by challenging their reasoning. The issue is not WHO is making the complaint or whether they are well-informed. The issue is HOW Lindsey responds to the complaint. She defeats one reason for the opinion and concludes the opinion is false. The flaw is structural (incomplete refutation), not epistemic (unreliable sources). Even if the complainers were perfectly informed experts, Lindsey's logical error would be identical.

   14%
2. B

   Correct56% picked this

   infers that an opinion is false merely because one potential reason for that opinion

   Why this is right

   This answer precisely identifies Lindsey's logical error. People claimed the company's decision was unfair, and one supporting reason was that the company had large profits (or profits had increased). Lindsey showed that this particular reason is factually weak — profits were actually smaller. So far, so good. But then she makes the leap: since this one reason is undermined, the entire opinion must be wrong, and the company acted fairly. This is a textbook incomplete refutation. An opinion can rest on multiple independent reasons. The employees might believe the decision was unfair because of contractual promises, precedent, management compensation, industry norms, or other factors Lindsey never addresses. By treating one challenged reason as the entire foundation for the opinion, Lindsey dramatically overstates what her evidence accomplishes. She refuted one premise and concluded she had refuted the conclusion — but conclusions can survive the loss of a single supporting reason if other reasons remain intact.

   Skill tested: Flaw · how this choice captures the argument's function is the move to repeat next time.

   56%
3. C

   Wrong Flaw2% picked this

   dismisses a claim on the basis of certain irrelevant attributes of the people who

   This answer describes an ad hominem fallacy — dismissing a claim by attacking the character or attributes of the people making it rather than addressing the substance. But Lindsey does not attack the complainers personally. She does not question their intelligence, motives, credibility, or character. Instead, she directly engages with one factual claim they rely on (the profit level) and attempts to refute it. Lindsey's flaw is different: she engages with the substance but treats her rebuttal of one supporting reason as a complete refutation of the opinion. She deserves credit for engaging with the argument — she just does so in a logically incomplete way.

   2%
4. D

   Bad Evidence Match22% picked this

   confuses the size of a quantity with the amount by which that

   This answer accuses Lindsey of confusing the size of profits with the amount by which profits increased — conflating absolute levels with rates of change. But Lindsey does not make this mathematical error. Her argument about profits is straightforward: people thought profits were large (or had increased), and Lindsey points out that profits were actually much smaller. She does not mix up "total profits" with "profit growth." Her error lies elsewhere — in the logical leap from "one reason for the opinion is wrong" to "the opinion itself is wrong." This answer identifies a mathematical confusion that is not present in the argument.

   22%
5. E

   Not Present5% picked this

   overlooks the possibility that a policy can be fair even when it

   This answer suggests Lindsey conflates fairness with generosity — perhaps arguing the company was fair when the real issue is that it was not generous. But Lindsey does not slide between these concepts. She directly argues the company's decision was fair, and the complainers directly argue it was unfair. Neither side introduces or confuses the concept of generosity. Lindsey's actual flaw is structural: she shows one reason for the unfairness claim is wrong and leaps to the conclusion that the company acted fairly. This is an incomplete refutation error, not a semantic confusion between "fair" and "generous." The flaw described in this answer simply is not present in Lindsey's reasoning.

   5%