Q4 - Journalist: A manufacturers' trade group

[ohthatpatrick]

Question Type:
Flaw

Stimulus Breakdown:
Conclusion: BI is not a member of the trade group.
Evidence: The trade group sent a list with hundreds of companies on it, and verified that every company on the list is part of the trade group. BI was not on the list.

Answer Anticipation:
It's the ol' Conditional Logic flaw. The claim that "every company listed in the document belongs to the trade group" is a conditional, signified by the universal word EVERY.
"listed in doc --> part of trade group"

Our author is reasoning that
Since BI is "~listed in doc", then BI is "~part of trade group".

This is an illegal negation. I could hand you a list of ten US states and say "every state listed on that piece of paper is part of the United States". That doesn't mean that one of the forty states I left off the piece of paper is NOT part of the United States.

Correct Answer:
B

Answer Choice Analysis:
(A) Does the author need to establish that BI "wants" to be in the group? No. We're just debating the truth value of whether BI is in the group or not.

(B) Yes! Does the author need to establish that the list covers ALL members of the trade group? Of course, because her reasoning goes "if you weren't on the list, then you aren't part of the group". She was assuming "if you're part of the group, you'd be on that list".

(C) Does the author need to establish the details of how the trade group accidentally leaked a list? No, because that has nothing to do with the central reasoning, which is "if you weren't on the list, you're not part of the trade group".

(D) We're getting really lost in the weeds here. It combines the out of scope "want" from (A) with the out of scope "secrecy" from (C).

(E) It's not very well established that the rep had reason to withhold info. If LSAT wanted us to be this skeptical of someone, they'd give us better grounds for doing so. Furthermore, we would only get suspicious that the rep was withholding info if they DENIED that some companies on the list were part of the trade group. Since the rep confirmed that all the companies ARE part of the trade group, he was really providing info, not withholding it.

Takeaway/Pattern: This isn't the easiest Conditional Logic Flaw to spot because students often don't see Universal words as triggers (any, each, all, every, no, none). And the correct answer choice is a litte weirder than average because it avoids "nec vs. suff" language and avoids providing a counterexample ("fails to consider that a company could belong to the trade group but not be on the list"). Correct choice (B) still captures these concerns, just with slightly unexpected wording.

#officialexplanation

[ca_teran1]

Why not e? Why b? Thanks

[sumukh09]

Stimulus says

If listed ---> belongs to trade group but then erroneously concludes that if not listed ---> does not belong. It is a flaw to negate the sufficient condition and negate the necessary condition as a result - this is called mistaken negation.

B describes this flaw -- just because a sufficient condition triggers a necessary condition does not mean that there is no other way to trigger that necessary condition. In other words, just because if you are listed entails belonging to the group does not imply that there is no other way to belong to the group. Maybe there are other documents that have other companies who belong to the trade group.

E is incorrect because we have no evidence that the representative had a reason to withhold information. What reason is E talking about? Just because they kept the list secret does not mean they had a particular reason to do so.

[wgutx08]

E is incorrect because we have no evidence that the representative had a reason to withhold information. What reason is E talking about? Just because they kept the list secret does not mean they had a particular reason to do so.

I don't think E is incorrect for this reason. The trade group has been trying to withhold the list until it inadvertently came out, I would say the representative does have a very good reason -- the same reason why the group kept the list secret-- to further withhold the information.

My take is that the accuracy of the statement of the representative simply does not matter for the argument since it is only about the companies that are in the document. Bruch, as we know, is not in the document.

[phoebster21]

Oh! I see now why E is incorrect.
The conclusion of the argument is about Bruch industries not being a member of the trade group. This is in no way related to what the representative confirms.

[chris.cole]

If we have A->B
Is B-> Not A a legal counter example

[BogdanC356]

But how do I know when a section of the argument counts as "evidence"? Every part of the argument is an assumption you must take for granted. Maybe if it says something specific about a claim. Like if the journalist somehow confirmed the list had the names of every single trade group in it. Maybe.

[ohthatpatrick]

To the previous-previous poster, no, "B, ~A" is not a counterexample to A --> B

If you play in the NFL, then you're male.

If I tell you, "Johnny is male, but he DOESN'T play in the NFL", have I contradicted the original statement?
Nope.


The only way to do a counterexample to a conditional is to
TRIGGER, but NOT-CONSEQUENCE

If A, then B.
counterexample: something that is A, but ~B



To the last poster, I can't tell what you're saying or asking. You know if part of an argument is evidence the same way a judge decides whether something is evidence in her courtroom: is it relevant to the claim being evaluated?


In a courtroom, the claim being evaluated is GUILT / INNOCENCE in regards to a specific charge.
In an LSAT argument, the claim being evaluated is the CONCLUSION.

The author's conclusion is that
"B.I. is not a member of the trade group"

To find evidence, ask yourself, "Hey, author, why should we believe that?"

Any claims the author made that sound like part of her answer count as evidence.

The first sentence here could be debatably called background or evidence. The author's answer to "Why should we believe that B.I. is not a member of the trade group" would be

"because B.I. is not listed on the document, and all the companies listed on the document belong to the trade group".

It sounds like you're calling stuff you're reading Assumptions. That could be a dangerous source of confusion. Assumptions, by definition, are invisible, unstated ideas.

If you can read it, it's not an Assumption.

It seems like you're torturing yourself here based on the idea that MAYBE other pieces of evidence also exist.

Okay, well, if so then the author should have presented those other pieces of evidence. Since she hasn't yet convinced us of her conclusion, those other pieces of evidence could strengthen her case.

Her argument is currently flawed (i.e. she did not successfully PROVE her conclusion) because we don't know whether some other note on the document informs us that these are the only companies in the trade group.