Logical Reasoning

PT106 · S2 · Q20 The report released by the interior

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The report released by the interior ministry states that within the past 5 years the national land-reclamation program has resulted in a 19 percent increase in the amount of arable land within the country.

Evidence

Report says that within last Source A claims 5 yrs, this program achieved fact Y. a 19% increase in the amt. of arable land.

If that 19% is right, If fact Y is true, the program has been then Z follows. a huge success. (Y → Z)

But the brilliant Senator A Respected says the program could not source B says have been a huge success. Z cannot be true

Conclusion

Thus the figures can't Source A must be be accurate. wrong about Y

Evaluate

What's wrong with this argument? It looks like it's offering a conditional statement and triggering the contrapositive in order to derive the conclusion.

I guess the issue is just that the conclusion is overly confident in the trusted source. When we're relying on a trusted source, we should conclude that what they're saying is likely correct, not definitely correct.

This seems to even test the Famous Flaw of Inappropriate Appeal, since it identifies Senator Armand as a brilliant mathematician, but what does that field of expertise have to do with judging whether the land-reclamation program could have successfully increased arable land. You'd have to be an agricultural expert for your opinion to really matter in this domain.

Goal

The crucial parts of this argument are these ideas:

Premise 1: If Y is true, Z is true. Premise 2: But this trusted source says Z can't be true. Conclusion: Thus Y can't be true.

The conclusion is flawed because it's too sure of itself, and the "trusted source" doesn't seem to be an expert when it comes to the issue at hand. Meanwhile, the source being contradicted is the Interior Ministry, who does seem like a relevant expert on this matter.

20.

The argument above exhibits an erroneous pattern of reasoning most similar to that exhibited by which one of the following?

  1. Albert’s father claims that Albert

    Weak Premise Match

    This argument doesn't have the implication of the original claim. It also doesn't have an "expert" source debunking an implication of the original claim. The original argument was like Premise 1: Source 1 claims Y is true. Premise 2: If Y is true, Z is true. Premise 3: But this trusted source says Z can't be true. Conclusion: Thus Y can't be true. This argument doesn't have any conditional like P2. And source 2 is not being identified as a very credible source. This answer is more like this: Premise 1: Source 1 claims Y is true. Premise 2: But source 2 contradicted claim Y. Conclusion: Thus claim Y isn't true. Our only objection to this argument would be "what if Albert was wrong or lying in terms of what he claimed?" That's fairly close to the original, but it seems way more fair to trust Albert when it comes to whether or not he knows where the spare keys are than it did to trust some random Senator who's good at math about whether arable land has increased.

    1% picked this

  2. Gloria’s drama teacher claims that

    Weak Premise Match

    This one is just like (A). We have a source 2 contradicting something source 1 said or implied, and the conclusion is still flawed because it's overconfidently certain that source 2 is providing good info. But, again, it lacks the Inappropriate Authority aspect of the original. It's reasonable to trust Gloria, who attended every class, when it comes to whether she was given an opportunity to act in at least one play. We shouldn't be 100% sure, but trusting Gloria is way safer than trusting the Senator, who was more external to the thing being discussed (unless the Senator is somehow part of the land-reclamation project, but we weren't told that).

    3% picked this

  3. Amos claims that he can

    Weak Premise Match

    This one is just like (A) and (B). It does have Source 2 contradicting something that Source 1 said or implied, and it unconditionally sides with Source 2. But again it lacks the Inappropriate Expert part of the original argument. It sounds like Dr. Treviso is just the right kind of expert you'd trust to judge whether someone is physiologically capable of holding their breath for 30 mins.

    22% picked this

  4. Evelyn reports that she got

    Wrong Flaw

    This has Source 2 contradicting Source 1, but Source 2 is always right about the thing he's talking about (time). Furthermore, the last couple ideas here get into a different flaw: Necessary vs. Sufficient confusion. If Robert is right, Evelyn couldn't hear late news. According to Evelyn, she didn't hear the late news. (that establishes the outcome, but we're not allowed to derive the trigger from that). Yet, the author does go and conclude that since the outcome was true, the trigger must be true; Robert must be right, which means Evelyn was wrong.

    5% picked this

  5. Correct

    Moira, after observing the finish

    Why this is right

    Again we have Source 2 contradicting Source 1, but this time Source 2 is an Inappropriate Expert (just like in the original), whereas source 1 actually seems like a more knowledgeable party. Moira actually observed the end of the race, whereas Lomas is just an expert on how bikes get made. If the issue at hand is "did Lee finish ahead of Adams?", it seems like Source 1 is the more trustworthy source.

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

    70% picked this

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