Q24 - Nightbird is an unsigned painting

[ohthatpatrick]

Question Type:
Weakens

Stimulus Breakdown:
Conclusion: Nightbird must have been done by one of L's students.
Evidence: Nightbird was painted in L's style, and was painted by either him or one of his students. And it has a pigment in it that doesn't appear in any of L's known works.

Answer Anticipation:
The key reasoning: Since the painting has a pigment that L was never known to use before, the painting must not have been done by L but rather by his students.

Couldn't we just say, "Okay, he had never used it before in any painting we know of … maybe he just wanted this special pigment this once for this painting? Maybe he's used it a bunch of times, but we just don't have access to those paintings?"

Correct Answer:
C

Answer Choice Analysis:
(A) Since the author is assuming that one of the students used this unusual pigment, does this idea go against that? Not really, since it's compatible with (A) that there are SOME exceptions, SOME students who do stuff differently than L (we only need one to explain the painting of Nightbird). But we could also say that "painting techniques" questionably even includes 'pigment choice'. Deciding on which pigments (colors) I'm using might not properly fit under the umbrella of what techniques I'll use to paint.

(B) It makes no difference what proportion of L's paintings were signed. Remember, the core argument is "since L had never used this pigment before, L didn't do this painting, one of his student did."

(C) Yes, this makes it equally unlikely that one of L's students did the painting. Since the author said that experts think the painting was either done by L or one of L's students, the "evidence" the author introduced about orpiment is completely meaningless. Since neither L nor the students have ever used this opriment (that we know of), orpiment will not help us decide whether the painting was done by L or his students.

(D) Out of scope: "important" artist?

(E) Unclear effect, but does more to strengthen than anything else. It sounds like orpiment came after L's time and DURING the later part of L's students' careers.

Takeaway/Pattern: The author's conclusion is SURE of itself. The fact that the painting has orpiment PROVES students, not L. But (D) shows us that orpiment doesn't point in favor of L or L's students.

#officialexplanation

[hyewonkim89]

I got this question right at first then was tricked by (B)..

At first, I didn't like (B) because I thought the stimulus was implying that Larocque's works are signed since the stimulus says "indistinguishable from that of Larocque."

When I re-did this question, I didn't really like (C) because it says "currently recognized." I figured it really wouldn't weaken the argument if there is unrecognized work by a student that contains orpiment.

How is (C) better than (B) and how can I prevent from being tricked by such a question again?

Thanks in advance.

[csunnerberg13]

Here's a breakdown of the answer choices in this question

Our argument is:

nightbird contains orpiment, a pigment never found in a work done by Larocque + nightbird is done in a style indistinguishable from Larocque and if it wasn't his, it was one of his students --> nightbird must have been done by one of his students.

We're trying to weaken this argument. Predicting weaken/strengthen answers is tough for me, so I just jumped into the answers with this knowledge of the core.

(A) doesn't tell us anything about the core or about the specific painting we're trying to determine the source of. Few of them ever deviated from what he did...so what? Was nightbird by them or not?

(B) just tells us that Larocque didn't sign anything. I can see why this is tempting - you're probably thinking this indicates it might have been made by Larocque, but that's not necessarily true. (B) still doesn't address the important issue of our core: we are troubled by this orpiment business, not by the lack of signature. We want to know something about why the orpiment could have been used by Larocque, if we were to learn anything about him that was helpful for weakening.

(C) is the answer. Instead of telling us something about how Larocque could have used orpiment like I just mentioned, this just tells us that none of the students were known to use orpiment either. This weakens because then the fact that orpiment wasn't found in a work of Larocque's can't get us to the conclusion that the students must have done it - the students probably didn't use that technique either, so there's no reason to conclude they did it.

(D) is irrelevant. we don't care if they are considered important, we're trying to determine the source of the painting.

(E) also irrelevant.

[jewels0602]

hyewonkim89, same thing happened to me.

During a timed run, I chose the correct answer (C) but after, when I was reviewing, I thought B was much better.

I am still a bit confused about why B isn't better; if Larocque never signed his paintings then it opens up a huge possibility that we don't know about all his paintings in existence, so perhaps one or few of those unknown paintings contain the orpiment, and that would weaken the argument.

Also answer choice (C) says "currently recognized" maybe there are some pieces that aren't recognized.

None of them are airtight, but I thought B weakened it more.

EDIT
I reviewed this again and I think I have a better understanding of why C is the correct answer.

The stim reasons that the painting isn't by Larocque because orpiment isn't found in any of his painting.

MOREOVER, the stim goes on to claim that it must've been done by one his students.

We are asked to weaken this claim.

C) is the correct answer because it uses the same method to dismiss (weaken) the conclusion as the author herself uses in the stim. So if author accepts the claim that not having orpiment is sufficient to say painting not done by Larocque, then by this standard it should be equally sufficient to say it's not done by any of his students.

B) is wrong because it asks for greater assumptions; 1. which is there are potentially unknown Larocque paintings out there and 2. these unknowns could have orpiment.

I wonder if this reasoning is adequate for further use?

[gaheexlee]

C) is the correct answer because it uses the same method to dismiss (weaken) the conclusion as the author herself uses in the stim. So if author accepts the claim that not having orpiment is sufficient to say painting not done by Larocque, then by this standard it should be equally sufficient to say it's not done by any of his students.

B) is wrong because it asks for greater assumptions; 1. which is there are potentially unknown Larocque paintings out there and 2. these unknowns could have orpiment.

I wonder if this reasoning is adequate for further use?

I used the same technique you did to choose (C) as the answer The stimulus assumes that lack of evidence leads us to assume something about Larocque, so we use that against the stimulus by saying that the same reasoning (lack of evidence) can also lead us to assume the same thing about his students.

POE also eliminates all other answer choices. (B) is tempting but like you pointed out, it requires too many assumptions. That Larocque never signed anything can go both ways: either that his paintings are everywhere without our knowing, or that they are confined to the few we already know of. Additionally, (B) doesn't as directly sever our "lack of evidence about orpiment -> not Larocque" relationship.

[daijob]

So the experts are wrong here, right?
They argue that if it is not Larocque, then it must be the students because there are only 2 options, but actually it is not?
I thought we accept premises, but we can doubt it?

Thank you