Q25 - All any reporter knows about

[andyevans000]

Got completely lost in the language on this one. Tried to diagram but that just proved to waste time and confuse me even more. Please help!

Thanks!

[cyruswhittaker]

Within this argument is a chain of conditional logic, and a conclusion that rests on a invalid negation.

From the argument, we know that

IF (press agent told every reporter)--->

THEN (no reporter can scoop)

The conclusion (remodified to express the conditionality of the statement) is

IF (press agent DID NOT tell every reporter)-->

THEN (at least one reporter can scoop)

Notice that this is a invalid negation of the above statement. Negating the sufficient condition of a statement does not ensure the negation of the necessary statement. In other words, a necessary condition can still occur despite a negative sufficient condition. This is what the author fails to recognize, and what is expressed in (E).

So, it COULD be true that we have

IF (press agent DID NOT tell every reporter)-->

THEN (no reporter knows any more) -->

THEN (no reporter can scoop)

Thus, the conclusion that "it follows" that "some reporter can scoop" from "press agent did not tell every reporter" is not true. It is entirely consistent that an alternate conclusion follows (no reporter can scoop) from this information. Notice that choice (E) plainly represents the first two lines of the conditional statement above.

Incorrect Choices:

(A): The statement "however, the press agent..." is inclusive of this statement. Failing to explicitly present it is thus not a flaw of the argument.

(B): The conclusion is about what a reporter "can" do. Whether the reporter actually does it is irrelevant.

(C): The conclusion is a broad claim that some reporter "can" scoop. Not acknowledging that there is a possibility that some reporter may have told something about the accident is not a flaw.

(D): Failing to recognize this is not a flaw. Afterall, maybe the press agent told everything he/she knows to a single reporter. So, they would both know the same amount about the accident. This has no bearing (based on what is presented in the argument) on whether that reporter "can" scoop all of the other reporters. In fact, it seems very likely that he/she could.

[lhermary]

I don't get why A is wrong here.

'However, the press agent did not tell every reporter everything about the accident.'

so if the press agent did not tell any reporter everything then both statements are correct, the stimulus statement and answer A, and the conclusion is false.

Where did I go wrong?

Thanks

[d.andrew.chen]

Literally had to look at this for four minutes when I just took this test. Completely missed the conditional idea at first (idiotic, I know) and that the question stem is sort of misleading. It's a flaw question, but one that sort of asks you to make inferences for a conclusion. The crucial conditional aspect is very well hidden by the wrong answer choices. None of them apply at all to the flaw they're looking for, as they all don't match the conditional nature of the question (A simply restates part of the clause that is the flaw...so it obviously can't be the one it fails to recognize!). At the end, your answer is merely one of the clauses in the chain...and the one that isn't used in the incorrect conclusion the argument establishes.

Correct Argument in Stimulus:
Press Agent Says Everything --> ~Some Reporter Knows More
~Some Reporter Knows More --> ~Some Reporter Can Scoop All

~Some Reporter Knows More = No Reporter Knows More

Argument in the stimulus:
~PA Says Everything -->Reporter Can Scoop All

(I think the argument assumes the chain...
~PA Says Everything-->Some Reporter Knows More-->some reporter can scoop)

Basically taking two mistaken negations in a row, it looks like. In any case, it's a mistaken negation. If you look at the first statement, the sufficient clause is that the "PA Says Everything," with the necessary clause that "No Reporter Knows More"...
So by invoking the negated clause "~Press Agent Says Everything" as the new sufficient clause, it does NOT rule out that "No Reporter Knows More," which is merely necessary to "PA Says Everything." Negating the sufficient does not rule the necessary statement. In fact, we actually cannot infer anything from "No PA Says Everything,"...we can only conclude it, due to contrapositives. The fatal flaw is that the argument attempts to use it as a sufficient clause.

Note that the flawed part (after "However") would be valid if sufficient/necessary were flipped.

~No Reporter Can Scoop All --> ~PA Says Everything
through contrapositives of each statement in the rules.

[ManhattanPrepLSAT1]

Nice work d.andrew.chen! You have it exactly right. Seeing the conditional logic here can be really useful, but also understanding the question stem is as well.

Suppose you saw the following argument:

A --> B
B --> C
---------
C --> A

and the question stem asked you to figure out how the argument is flawed because it failed to consider that something is consistent with the facts. The only thing that could be consistent with the facts that would show an error in reasoning would be something that would show why the conclusion doesn't follow from the evidence.

Since the conclusions says that "all C's are A's", the correct answer should show that such is not necessarily true that, "some C's are not A's" - which is consistent with the two premises.

So when I saw this question, I realized that they wanted me to find something that would challenge the conclusion but be consistent (not contradictory to, though not necessarily following from, the premises). Notice that the correct answer is simply the logical opposite of the stated conclusion.

For another example of the exact same issue, check out PT25, S4, Q23.

Hope that helps!

[WaltGrace1983]

So I understand why (A) and (B) are wrong and I understand why (E) is right. However, are (C) and (D) wrong because they still don't answer the critical question of, "but do the reporters actually know more or not?!"

In this question, we would want to show why it is NOT TRUE that some reporter knows more and, thus, consequently show that IT IS NOT TRUE that "some reporter can scoop all the other reporters."

(C) gets us close to the flaw but doesn't actually get at the critical element. Even though all the reporters know something this doesn't necessarily mean that no reporter knows no more than any other reporter and it doesn't necessarily mean that some reporter does know more than any other reporter.

(D) The press agent isn't really involved here. We want to know about the reporters and how much they know. In addition, I feel like (D) might actually be the opposite of what we want. If there is a most knowledgable, then this seems to meet that some reporter DOES know more than any other reporter. If this is the case, we still cannot prove anything.

(E) This gives us what we want. If "no reporter knows any more about the accident than any other reporter," then we KNOW that scooping is impossible. In addition, this is perfectly consistent with the rest of the argument.

[michaelwcarper]

I answered A originally, and I think my issue was the weird wording of the question. "The reasoning is flawed b/c the argument fails to recognize which one of the following is consistent with the facts the argument presents?"

So the correct answer will
1. Logically follow from the stimulus
2. Disprove the conclusion

A was tempting for me, since it both logically follows from the stimulus AND it COULD disprove the conclusion.

Because if "the press agent did not tell everything about the accident to any reporter," he might have told 90% of it to every reporter. Thus no reporter knows more, and no scoop. HOWEVER he also could have told most of them 80%, but only one 90%. In which case, a reporter could scoop the rest. Such a scenario is logically consistent with the argument, but doesn't disprove the conclusion. So A could disprove, but that would require further assumptions.

E, on the other hand, must disprove. If "no reporter knows more about the accident than any other," it doesn't matter if they all know 100% of the story, or they all know 80%. And this is a sufficient condition for not being able to scoop, as the stimulus tells us.

[cyt5015]

I understand that for answers C and D, even if we replace "may" with "does", the two still cannot be the correct flaw to this argument. However, someone in this forum brings up another perspective to eliminate answer C and D that because the conclusion is only describing a possibility by using "can", answers having "may" are compatible with this conclusion, therefore, are not the correct flaw. Only facts like answer E can wreck the argument. Is that a good way to approach this question? Thank you!

[sh854]

Can someone explain this without the conditional diagramming? What is the flaw occurring here?

[maryadkins]

I'm not sure how to explain this without conditional formatting. That's how we break it down. Otherwise it's just a bunch of facts and you're trying to find the gap in them. You can jot them out if conditional formatting intimidates you and just look for the missing piece that way if you like, but learning conditional logic and using that to approach this is going to be more efficient and, in the end, likely the only way to correctly and efficiently answer this kind of question.

[OscarD100]

Michaelwcarper gave a great answer

Here's my wording

(B) and (C) can be ruled out for reasons pointed out in other posts above.

(D) The PA may not know any more about the accident than the most knowledgable reporter.
The first line says: ALL any reporter knows is what the PA has said.
So even the most knowledgable reporter knows nothing without the PA.
If the PA knows no more than the most knowledgable reporter, then the PA knows nothing.
This conclusion turns the second sentence of the argument into nonsense and guts the whole argument.
We can't completely rule this answer out, but let's sideline it as a 'weak' answer.

(E) No reporter knows any more about the accident than any other reporter.
If we insert this sentence into the argument it is consistent with the facts because:
It is possible that the PA told every reporter some things (or nothing) and
therefore, every reporter knows exactly the same amount as the others
which means no one can scoop.
This answer is consistent with the facts of the argument AND makes the argument flawed
This is our best choice so far

(A) The PA did not tell everything to any reporter.
If we insert this into the argument it is possible that:
1) The PA told every reporter some things (or nothing) and
therefore, every reporter knows exactly the same amount as the others
which means no one can scoop.
This is consistent with the facts AND makes the argument flawed
BUT
It is also possible that:
2) The PA told some things to some reporter and less to others
If this is the case it follows that some reporter can scoop all of the other reporters
Which makes the arguer's statement correct and, therefore, NOT flawed.

(A) is an answer that could lead to the conclusion POSSIBLY being flawed
but
(E) is an answer that leads to the conclusion DEFINITELY being flawed

So (E) is the BEST answer

[mzm13]

have the exactly same drawing as you, but i cannot refer to choice E, the language is too complicated.

Nice work d.andrew.chen! You have it exactly right. Seeing the conditional logic here can be really useful, but also understanding the question stem is as well.

Suppose you saw the following argument:

A --> B
B --> C
---------
C --> A

and the question stem asked you to figure out how the argument is flawed because it failed to consider that something is consistent with the facts. The only thing that could be consistent with the facts that would show an error in reasoning would be something that would show why the conclusion doesn't follow from the evidence.

Since the conclusions says that "all C's are A's", the correct answer should show that such is not necessarily true that, "some C's are not A's" - which is consistent with the two premises.

So when I saw this question, I realized that they wanted me to find something that would challenge the conclusion but be consistent (not contradictory to, though not necessarily following from, the premises). Notice that the correct answer is simply the logical opposite of the stated conclusion.

For another example of the exact same issue, check out PT25, S4, Q23.

Hope that helps!