As an experienced labor organizer and the former head of one

E.

Explanation:

Premise: an experienced labor organizer and the former head of one of the nation’s most powerful labor unions.
Conclusion: excellent choice to chair the new council on business-labor relations.

The correct answer will assist in establishing the conclusion / fix a weakness in the argument.

The argument is flawed in that it assumes that his role as a labor leader will prepare him for business relations.

E. strengthens the argument by basically confirming that assumption. Negating E will weaken the argument by making him look under-qualified.

As far as B, I would say PowerScore would describe it as a shell game answer. It doesn't support this conclusion per se, but it looks like it does.

On further examination, I was hasty in eliminating (E). (E) certainly strengthens the answer--"only" makes it too extreme to be an assumption, but the argument is strengthened indeed if the only qualification necessary is the one he has.

That being said, the reason that I eliminated (E) was that there isn't actually anything wrong with (B); it directly reaffirms the assumption. Once I saw that it matched our prediction perfectly, I hastily assumed that the others had to be wrong. I suppose in this case an argument could be made that is strengthens the argument 'less' than (E) does, because of the introduction of the idea of business "leaders". However, (B) directly bridges that gap between the evidence (Grayson's work as a labor leader) and the conclusion (his ability to work in business-labor relations.) The real GMAT never has answers that 'strengthen less' and 'strenghten more'; there will be four answers do not strengthen the argument, and exactly one that does. I've heard a lot of complaints about the quality of the 1000 CR questions, and I think this is another example.

Still, Suvorov, thanks for pointing out my hastiness with (E)!

Similarly, I didn't want to start a Kaplan/Manhattan turf war, so rather than use our materials I turned to the Official Guide. I spent about 45 minutes skimming through the answers and explanations for an example of a "slightly strengthens, but not enough" wrong answer, and I couldn't find a one; every Strengthen/Weaken I saw had four wrong answer choices that were out of scope or 180 degree wrong, and only one choice that Strengthened or Weakened. I stand by my statement that the actual GMAT won't have a trap like (B).

I think the total answer is somewhere between the two of us. I in no way want to contradict a fellow instructor, and Eli is correct in that there should always be one answer choice that strengthens or weakens MUCH more strongly (making the others looks wussy and out of scope in comparison with its awesomeness). However, it is simply not true that there will NEVER be other answer choices that also strengthen or weaken. There's a reason the question is worded as it is:

"Which of the following, if true, would MOST strengthen the conclusion above?" [emphasis mine]

Inherent in that "most strengthen" is the idea that multiple answer choices could strengthen the argument, but if they do, one will strengthen MORE. I shouldn't have to prove this, because the wording of the questions is very straightforward on this subject, but there are indeed MANY questions with slight strengthens or slight weakens. This is merely the first question we teach in our strengthen/weaken section. It's from the OFFICIAL Guides (Verbal Guide - #23) -- Answer choice A definitely strengthens, but C strengthens more:

Near Chicago a newly built hydroponic spinach “factory,” a completely controlled environment for growing spinach, produces on 1 acre of floor space what it takes 100 acres of fields to produce. Expenses, especially for electricity, are high, however, and the spinach produced costs about four times as much as washed California field spinach, the spinach commonly sold throughout the United States.
Which of the following, if true, best supports a projection that the spinach-growing facility near Chicago will be profitable?

(A) Once the operators of the facility are experienced, they will be able to cut operating expenses by 25 percent.
(B) There is virtually no scope for any further reduction in the cost per pound for California field spinach.
(C) Unlike washed field spinach, the hydroponically grown spinach is untainted by any pesticides or herbicides and thus will sell at exceptionally high prices to such customers as health food restaurants.
(D) Since spinach is a crop that ships relatively well, the market for the hydroponically grown spinach is no more limited to the Chicago area than the market for California field spinach is to California.
(E) A second hydroponic facility is being built in Canada, taking advantage of inexpensive electricity and high vegetable prices.

Now C is clearly better here, but that doesn't change the fact that A DOES strengthen (operating expenses are quite high, so if operating expenses get cut, that should help the factory be profitable). There are many other similar examples throughout the OG.

Hope that helps!

Hey Vikuba,

C says that the person MUST have a skill that we are not sure from the passage Grayson has. Look specifically at the difference between what we're told about him, and what answer choice C says the position requires. They ARE NOT the same thing.

E is way more specific. It says that the person who fills the post must have EXACTLY the skills the passage itself tells us Grayson has.

Hope that helps!

I'm afraid I have to disagree; this situation isn't comparable to the 1000 cr question problem in the original post. The difference is that in this problem, A) seems to strengthen the answer, but actually doesn't. Note the bolded part--with the information in (A), we will have spinach that begins costing four times as much as other spinach, and ends up at three times as much as regular spinach. (A) could be said to weaken the argument, since it makes it less likely that the fancy spinach will drop to a price comparable to that of regular spinach.

In the original question, (B) bridges the logical gap in the original argument--that experience leading labor organizations qualifies Grayson to manage relations between business and labor. (B) is neither definitive nor conclusive, but it does strengthen that unstated assumption. In other words, (B) is wrong only because (E) is better, and if (E) weren't an answer choice, (B) could be correct. On the GMAT, each answer choice will be correct or incorrect in and of itself. Once you've found a correct answer you will never have to read the rest to make sure there isn't a second one that's even more correct.

I think we agree in the main, though we disagree about the details. I do think there are shades of strengthen/weaken in many questions (hence the way in which the questions are asked.

In the case of the spinach question, the "costs four times" refers to the cost to consumers, hence the following phrase comparing it to California field spinach being "sold". If they meant to say it costs four times as much to produce, it would say that. Instead it says "the spinach produced costs about four times as much". Thus the problem is whether or not anyone will be willing to pay this ridiculous cost (which is why C is the right answer). However, if operating expenses are cut, it still strengthens the notion that the factory might be profitable (Profit = Revenues - Expenses). Thus this strengthens, however slightly.

In the Grayson example, his experience with business leaders does not lead us to the conclusion. Having "good relations" does not necessarily make you good at the job (plenty of great businessmen and politicians have difficult relationships with people they work with). That's an inference that they're hoping to force on the question. Only D relates to the premise as it's actually stated.

Well matched, my friend. Have the last word if you like, but I think I've said all I can say on this one.

Hope everyone enjoyed the lively debate!

Against my own promise, I wanted to point out at least one question in the OG that does feature two answer choices that both strengthen (and so could both stand alone as correct answers, if not for the other). Question 21 in Critical Reasoning in the 12th edition of the OG. In the explanation for the question, GMAC it says describes a wrong answer choice (E) thusly:

"This statement provides an example of learned bird behavior, and so provide a little additional support for the conclusion, but not as much additional support as does B." (emphasis mine)

There are plenty more where that came from, but even one should be enough to end this debate.

Extremely informative and well-meaning, well-reasoned discussions between the two experts. My kudos on your spirit. Exactly as Eli reasoned following the exact same steps as he did, I chose B. I wasn't convinced however - again exactly as Eli pointed out that GMAC would build ambiguity in choices. If a choice is wrong/incorrect/inappropriate - there's got to be a solid reason behind it. Looking at B - while it does well to bridge the gap - it further requires TWO more assumptions - 1) That the good relations Grayson maintained with the business leaders during his last tenure - would mean he would be able to do so in the current tenure also. This may or may not be the case and hence he may or may not be an appropriate choice now.
2) In fact he may not be an appropriate choice now even, because he might have done well in his last assignment but may have simply lost the touch to be a good leader now.

Choice E states that past experience in understanding of the labor problems is the ONLY prerequisite for the job. This immediately obviates the need for the two assumptions cited above - viz - that he should have good relations even now (or be able to forge good relations now)
and that he be good at his job even now (because this is clearly discarded as a prerequisite by choice E).

Hey Dwi,

Eli's explanation on this one is great. Our argument was more about the idea that GMAT wouldn't throw in ANY kind of ambiguity on a strengthen/weaken. Again, you can see my examples if you don't believe it, but the very wording of the questions is setting you up for more than one possible strengthen or weaken. Now I'll admit that it happens surprisingly rarely, but it does happen, as the book states, and my example exemplifies. I feel that Eli was too hard on himself for missing it, as if there were nothing attractive about B. It simply doesn't strengthen in regards to the underlying logic, but does provide a strengthening example. As for Suvorov pointed out, this is how the LSAT works, and LSAT "CR" has a lot in common with GMAT "CR".

Okay. Consider it put to rest. Eli is absolutely right that it's a highly rare occurrence, but I want room to be made for the few times it DOES happen.

-tommy

Wow, what a discussion!

Note that this is not an officially released GMAT question.

On real GMAT, We can always ignore the word "most". Only one choice will strengthen, while the other four will not. If this were not so, then the task would be that of comparing two choices both of which strengthen, and then using external criteria to judge which one is a "better" strengthener. Then the test would lose its meaning; would cease to be an objective barometer of test-takers' critical thinking skills. This would compromise the goals of the test-maker.

As everywhere else on the GMAT, there is one and only one answer that satisfies all the conditions of the question.

If this is not the case, then the question is bad. And, I have encountered a ton of bad questions from the 1000CR series. So, in any officially released GMAT materials, as Eli points out, there is only one correct answer to any type of question anywhere throughout the test. The burden of proving otherwise would rest on Tommy!

As an aside, Eli: "extreme" answers can easily be correct in strengthen/weaken, and in sufficient assumption questions. We should be wary of extreme answers in necessary assumption and in inference questions.

Kaplan Dudes,

I already proved it! Read the thread. I showed a question in which GMAC says that one answer choice strengthens, but not as much as the answer. How long does this have to go on? ONCE MORE, it is question #21 in the Critical Reasoning portion of the 12th edition, RELEASED BY GMAC.

-tommy

Hi Tommy,

sorry for not checking into that question. Frankly, I'm surprised at GMAC's explanation.

However, while it is strongly suggestive, I don't think it quite establishes that a choice will be wrong ONLY because it does not strengthen as much as another choice.

If we look at choice E of the question you cite, we see right away that it is outside the scope. The scope of the argument was "bowerbirds' building styles" while choice E discusses "song dialects".

Is a song dialect the same thing as a building style?...obviously not.

Choice E supports the more general idea that some things are learned rather than genetically transmitted. But it does not "strengthen the conclusion drawn by researchers" which is that "bowerbirds' building styles are a culturally acquired, rather than a genetically transmitted, trait."

Thus, despite GMAC's (surprising) explanation, there is a much better reason justifying chioce E's incorrectness:

it does not relate to the researchers' conclusion, and thus cannot be something that strengthens the researchers' conclusion. It, like the other three choices, simply fails to satisfy the conditions of the question.

In the OG question, while the GMAC's explanation is mystifying, again, the design of the question does not establish the inference that:

a choice will be wrong ONLY because it does not strengthen as much as another choice.

I will be convinced if I ever see an officially released question in which the ONLY reason to eliminate a choice is because it does not strengthen as much as another choice (still haven't).

While you may consider my position stubborn, I invite you to respond to or contemplate my observation that choice E of question 21 of OG12 is clearly outside the scope. Again, in every official question I've seen one and only one choice satisfies the conditions of the question. This question does NOT prove otherwise (although GMAC's explanation is baffling).

The reason I am defending this position strongly is that I think it is something very important for the test-taker to understand and trust: there is only one correct answer!

EDIT: In retrospect, GMAC's explanation isn't all that surprising. Their explanation is certainly one way of looking at it. But, as I wrote above, considering scope is another way of eliminating E. Again, I don't think GMAC's explanation of that question supports the more general (and more ambitious) idea that a choice will be wrong ONLY because it doesn't strengthen as much as another choice.

Okay Kaplan,

Question #35 also cites an answer choice, "This information is sufficient to justify a little doubt about the conclusion-but not at all specific enough to undermine the argument's conclusion as much as does (B).

As well as the one I already cited, in addition to the Chicago question, which I still think reveals two answer choices that strengthen (Profit = Revenue - Costs...if Revenue goes up OR if Costs go down, possibility of profit is strengthened), proves that this does occasionally happen.

Here's where we agree: CR is not subjective. There is always one correct answer choice. However, sometimes certain answer choices will strengthen some of the premises that support the main conclusion, leading to a bit of overall strengthening. This does not mean that these are the answers, or that there should even be confusion. However, that was the trap that Eli fell into when he first answered this question incorrectly, so I think it's important to note it as a trap. It is very possible that with just a bit of logical inference, multiple answer choices can be described as possible strengtheners. Only one answer choice will get at the heart of the conclusion and really strengthen that, without add-on assumptions.

Fair enough?

-tommy

Hi Manhattan,

again, you are citing from their explanations. None of their explanations assert that those are the ONLY logical explanations. Show me a question whose design proves that the ONLY reason to eliminate a choice is because it does not strengthen (or does not weaken) as much as another choice.

And "sufficient to justify a little doubt about the conclusion" is NOT the same as "weakening the conclusion.

Anways, perhaps scope vs. allowing for "better and worse" are just two different ways of looking at it.

But this:

[quote2tommywallach]Only one answer choice will get at the heart of the conclusion and really strengthen that, without add-on assumptions.[/quote2]

is exactly my point!

Definitely a mistake on my part; I found a 'right' answer, and then tried to eliminate the other.

I dropped out of this thread in hopes of keeping things peaceful, since I'm fairly confident a problem like the one in the OP won't make it into anyone's Test Day. But thanks you, Testluv for making my point about right and wrong answers a little bit clearer than I was able to! What I wasn't clearly explaining is that while incorrect answers may in some loose sense have a vague, theoretical impact on the author's assumption, the GMAT will have four wrong answers that are wrong for a specific reason--and that's not the case for the original problem here.

Incidentally, the OG is a wonderful source for problems, but NOT for explanations. Tommy, the problem you cite did explain that the answer doesn't 'undermine the conclusion as much', but the answer choice will still have a categorical flaw; not being strong enough is one, but not the only, reason to eliminate it. Take a look at the problem and explanation on page 83 of the 12th edition, a strengthen/weaken question, to see why I am hesitant to take OG explanations at face value: The statement that would strengthen one hypothesis and weaken the other is correctly identified, but the explanation misidentifies which hypothesis is strengthened and which is weakened.

I don't think I ever said that it would be the only reason. I just said there could be more than one answer that has a strengthen/weaken effect, though it may be fairly nebulous and not nearly as good as the correct answer. I think I've proven that point, through the GMAC explanations and my own. I say we leave it at that. Decide for yourselves, fair members of the gmatclub website!

-tommy