What qualifies as weakening an argument

[wj097]

Hello,

Ok.. so definition of weakener is straightforward (those that cast doubt on the required assumption of the argument), but in application, its hard to draw the line for what qualifies as "casting doubt on the assumption". Here is one example that I think exposes my thought process, and would be great to calibrate with the Geeks.

Example: This year Company A's revenue increased compared to last year. Therefore, Company A's profit must not have decreased over the year.

1. Company A's cost increased more than the revenue
2. Company A's cost increased at least as much as the revenue
3. Company A's cost increased over the same period
4. In determining the profitability of Company A, cost is also an important factor

1. Obviously weakens the argument.

2. We can think of two cases. If increased more, it weakens. If equal, conclusion is intact...however, the fact that there is an explicit case that does not require further assumption that the arguer can rely to rebut, it does not weaken. I think PT 22 4 26 (B) is a same kind of tempting answer choice. q26-a-member-of-the-british-parliament-t5946.html?hilit=overall%20happiness

3. well...depending on the how much it increased...but now we can't be sure about whether A's profit has not decreased..thus weaken

4. Just by saying its a factor, its further removed than 3. (we dont even know whether it increased) so does not weaken. Also, it is a premise booster as profitability is by definition revenue - cost. So it sure its a factor.


The more that I look into strengthen/weaken Qs, LSAC draws subjective line of what qualifies as proper strenthener or weakener and so for subtle cases like above cannot simply put into formula, but only as rule of thumb..what would you say??

Thx.

[ohthatpatrick]

I love your question and examples.

I disagreed with your assessment on 2 and 4. I think all four of your examples weakened. #1 was unique in that it REFUTED!

Remember that the correct answer to Strengthen and Weaken questions does not have to PROVE or REFUTE, it only has to make the argument more or less believable.

Sometimes it will make the argument MUCH more or less believable (like 1 or 2), other times only BARELY more or less (like 3 or 4). If it tips the scales in either direction, it strengthens/weakens.

I'm not sure why you thought
3. Company A's cost increased over the same period
would weaken but
2. Company A's cost increased at least as much as the revenue
would not weaken.

2 has a stronger weakening effect than 3. With 2, as you said, there is only ONE case in which the original conclusion would still have a chance.

With 3, there are an infinite number of cases in which the original conclusion would still have a chance.

I think you're reacting to the fact that with #2 you can come up with one specific interpretation that actually proves the conclusion is correct.

But just because #3 is vague doesn't mean we couldn't come up with tons of interpretations that would also prove the conclusion is correct.

It's really dangerous to measure these answers in terms of what they prove / don't prove. The correct answers are almost always somewhat wishy-washy, allowing for shades of gray. Our standard for Weaken need only be, "Does it introduce any new doubt?"

I think even this qualifies:
4. In determining the profitability of Company A, cost is also an important factor

Yes, LSAT would probably expect us to know via common sense that cost and revenue are both involved in profits. But if the hypothetical author of your example argument was dumb enough to ignore bringing up the costs, then an answer choice that reminds him of the relationship of cost to profit would still qualify as something important that was overlooked.

I agree that we should not devise a formulaic system for assessing whether something weakens, but let me suggest that there are four cases that would normally apply:

1. The correct answer weakens the argument core .. i.e. it calls into question the connection between premise and conclusion ... attacks the assumption(s)

2. The correct answer goes against what is said in the conclusion (an answer can Weaken merely by providing information that undermines the validity of the conclusion ... the answer does not HAVE to address the premise)

3. The correct answer undermines the trustworthiness of the evidence (while saying nothing regarding the Conclusion) ... this is particularly true when the evidence used is something sketchy such as a study/sample/survey/analogy/appeal to opinion

4. The correct answer brings up an overlooked possibility ... alternative cause / alternative interpretation of the evidence / potential way a plan could backfire / alternative interpretation of a statistic ... these somewhat relate to the gap in the argument Core, but they won't involve "naming a language shift assumption"

By the way, the same four categories apply to Strengthen; just switch polarity for each category.

Hope this helps.

[wj097]

I'm not sure why you thought
3. Company A's cost increased over the same period
would weaken but
2. Company A's cost increased at least as much as the revenue
would not weaken.

2 has a stronger weakening effect than 3. With 2, as you said, there is only ONE case in which the original conclusion would still have a chance.

With 3, there are an infinite number of cases in which the original conclusion would still have a chance.

I think you're reacting to the fact that with #2 you can come up with one specific interpretation that actually proves the conclusion is correct.

But just because #3 is vague doesn't mean we couldn't come up with tons of interpretations that would also prove the conclusion is correct.

It's really dangerous to measure these answers in terms of what they prove / don't prove. The correct answers are almost always somewhat wishy-washy, allowing for shades of gray. Our standard for Weaken need only be, "Does it introduce any new doubt?"

Thanks Patrick! I had and am having so much trouble with the issue and almost feel like I am over-engineering it. Surely, this discussion is going be my lifeline.

As for why I treated #2 and #4 differently and tried to squeeze out justification for myself was because of similar answer choices that were trap answers in the following questions

#2 (Overall happiness) PT 22 4 26 (B)
#4 (Wood burning stove) PT 34 2 25 (B)

I see that the correct answers are much stronger weakener, but nonetheless, I would say in the absence of the correct answer these tempting answers would be legitimate weakeners, however weak it may be. Which makes me think, there can be multiple weakeners in a question and our task is to select the one that most strongly weakens. Would you agree?? or are the above trap answers simply wrong for some other flagrant errors.

Thx

[ohthatpatrick]

Yeah, it definitely happens on occasion that more than one answer strengthens or weakens and we have to pick the one that MOST strengthens or weakens.

Luckily, this is rarely the case. Typically the other ideas are truthfully irrelevant.

When the test DOES force us to consider which answer strengthens or weakens MORE than another, it should be pretty clear based on strength of language.

The other general pattern you see in ranking one vs. another might be something like this:

Recently at Jackson High, the students who chewed gum during today's geometry quiz got higher scores than those who didn't. Clearly, chewing gum helps you focus on the task at hand.

Both of these answers would strengthen:
(B) Students who chewed gum at Lincoln High also got higher scores than those didn't.

(C) The students who chewed gum did NOT study for the quiz considerably more than the students who didn't.

But (C) would win. A somewhat parallel correlation with some other, possibly analogous situation is not nearly as powerful to LSAT as ruling out a possible alternative explanation for the observed phenomenon/statistic.

Per your examples:
#2 (Overall happiness) PT 22 4 26 (B)

(B) doesn't actually weaken because "a few people happy, with no increase in others' happiness" still represents an increase in the sum total of happiness. While "no increase" COULD mean "a decrease", this answer choice doesn't give us any nudge in that direction.

#4 (Wood burning stove) PT 34 2 25 (B)
(B) doesn't seem to weaken to me, because it gives me no reason for thinking that open fireplaces are more dangerous than wood ones. It tells me that the amount of creosote fluctuates due to other variables, but that doesn't in any way undermine the premise that wood-burning operating at a given frequency, using a given flame would still deposit more creosote than an open fireplace operating at the same frequency/same flame.

Hope this helps.