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Q15 - People who are good at

by tzyc Thu Mar 28, 2013 8:29 pm

What would the flaw be in the stimulus??
I just felt the second sentence and conclusion do not relate to the first sentence...same for (C).
I think (A), (D), (E) all have similar patterns and those are not flaw (A→B, A, thus B). (D) changes a word from write to publish, so that's wrong...
But I'm not sure the flaw in the stimulus.

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Re: Q15 - People who are good at

by ohthatpatrick Mon Apr 01, 2013 7:08 pm

LSAT rarely goes for TOTALLY irrelevant premises. (When we read an argument with two people talking, the 2nd person often objects to the 1st person but supplies an irrelevant reason)

But if you're reading one author's paragraph, try to figure out what the INTENDED match was.

Sometimes it helps to reverse-engineer the argument from the conclusion.

Conc: Mary would make a good Drackedary player

(What do I know about Mary? What do I know about "good Drackedary player"?)

Prem: Good at Drackedary --> skilled with their hands
Prem: Mary is a competent watchmaker.

Since we know the conclusion wants to fuse 'Mary' with 'Good at Drackedary', it must be assuming that "skill with hands" is a match for "competent watchmaker".

I'll admit, I was a little surprised by the outside knowledge LSAT demands for us to follow this assumption easily, but we can otherwise get it structurally.

Making watches involves careful manipulations of tiny little watch parts, so I guess it's natural to think that watchmakers might be skilled with their hands (still an assumption we would have to explicitly hear to logically prove the argument, but LSAT expects us to get that the author is assuming that connection).

So let's add in the assumption
"competent watchmakers are skilled with their hands".

What's wrong with this argument
Prem: Good at Drackedary --> skilled with hands
Prem: Mary --> competent watchmaker --> skilled with hands

Conc: Thus Mary would be good at Drackedary.

That was backwards logic!

We know Mary is skilled with her hands, but that doesn't guarantee us that she'd be good at drackedary. We can't read that first conditional in reverse.

If you didn't pick up on the fact that the first sentence was a conditional, take a look again and see what wording tells us it is.



"invariably" is strong enough to be conditional.

So there are really two flaws in the argument:
assuming 'skilled w/ hands' follows from 'competent watchmaker'
and
reading a conditional rule backwards

We should expect to see both those flaws in the correct answer.

(A) This is airtight logic. It is not flawed, so we can move on.
Daryl --> in Daryl's family --> have long legs --> make good runner.

(B) This looks promising. We have a conditional. We have a language shift between 'write for a living' and 'published novelist for many years'. Let's check whether we have backwards logic.
Write for living --> enjoy reading
Julie = published novelist
If we assume that published novelist -> write for living, then we get
Julie -> published nov. -> write for living -> enjoy reading

So that was close, but there was no reversed logic.

(C) Looks promising. We have a conditional and a language shift.
Race car driver --> Good reflexes
Chris = table tennis player
If we assume that table tennis player -> good reflexes, then we get
Chris --> table tennis player --> good reflexes

In order to infer that Chris would be a good race car driver, we have to read the original conditional backwards. We have our winner!

(D) The first sentence is NOT conditional, using the word "often", so we don't need to bother reading any further.

(E) We have a conditional and a language shift.
Good skier --> learn to ice skate eventually
Erica = world-class skier
If we assume that world-class skier -> good skier (and why wouldn't we), we get
Erica -> world-class skier -> good skier -> learn to skate eventually

Does (E)'s conclusion read the original conditional backwards? No, it just changes the final idea from "learning eventually" to "learning quickly". Not the same as the original.

Hope this helps.
 
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Re: Q15 - People who are good at

by foralexpark Sun Nov 17, 2013 12:33 am

[quote="ohthatpatrick"]LSAT rarely goes for TOTALLY irrelevant premises. (When we read an argument with two people talking, the 2nd person often objects to the 1st person but supplies an irrelevant reason)

But if you're reading one author's paragraph, try to figure out what the INTENDED match was.

Sometimes it helps to reverse-engineer the argument from the conclusion.

Conc: Mary would make a good Drackedary player

(What do I know about Mary? What do I know about "good Drackedary player"?)

Prem: Good at Drackedary --> skilled with their hands
Prem: Mary is a competent watchmaker.

Since we know the conclusion wants to fuse 'Mary' with 'Good at Drackedary', it must be assuming that "skill with hands" is a match for "competent watchmaker".

I'll admit, I was a little surprised by the outside knowledge LSAT demands for us to follow this assumption easily, but we can otherwise get it structurally.


Patrick,
I agree that there is a blatant assumption in this question:
competent watchmaker = skilled with hands.

so with that assumption in hand, A -> B, therefore, B -> A
which is a classic reversal error (as you explained so nicely in your response)

But looking at C, I think there is a similar, if not same, assumption embedded in the argument:
Table tennis player = good reflexes
I think this is a VERY similar assumption that the author is making in the prompt.

So my suggestion is,
I think the flaw in the prompt is an unwarranted assumption as well as illegal reversal. Hence C perfectly mirrors the prompt, since they both have reversal error + unwarranted assumption error.

Let me know what you think
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Re: Q15 - People who are good at

by ohthatpatrick Mon Nov 18, 2013 9:49 pm

I completely agree. :)

You may have missed this part in my original post that was agreeing with you:
So there are really two flaws in the argument:
assuming 'skilled w/ hands' follows from 'competent watchmaker'
and
reading a conditional rule backwards

We should expect to see both those flaws in the correct answer.
 
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Re: Q15 - People who are good at

by mrosa1210 Wed Feb 04, 2015 9:45 pm

Would it be a mistake to eliminate answer choices B,D, and E since they have a conclusion that does not include would?

Would doesn't have the same conditional trigger as "must" in answer choice D.

Would doesn't equate to could?
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Re: Q15 - People who are good at

by WaltGrace1983 Thu Feb 05, 2015 8:47 pm

mrosa1210 Wrote:Would it be a mistake to eliminate answer choices B,D, and E since they have a conclusion that does not include would?

Would doesn't have the same conditional trigger as "must" in answer choice D.

Would doesn't equate to could?


A geek might have to chime in here because I don't know if there is a real, theoretical, answer to this. However, I would be hesitant to eliminate an answer out of the difference in such a non-consequential word as "would."

I think "would" is still affirming the necessary condition. For example, "If he likes cookies, he WOULD like ice cream" = cookies --> ice cream I'd suppose.
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Re: Q15 - People who are good at

by ohthatpatrick Thu Feb 12, 2015 1:54 pm

I would echo Walt's hesitation.

Basically, sensing that B, D, and E have a different sounding/feeling conclusion is a great way to filter them out and focus your attention on whether A or C match the stimulus.

But I wouldn't actually ELIMINATE them, just de-prioritize them.

Generally speaking, Matching questions do tend to give us an argument in which the Conclusion of the correct answer is the same type / strength of conclusion as that of the stimulus. (although Match the Flaw is less verbatim than normal Match the Reasoning questions)

(E) is definitely a mile away. "Could" just indicates possibility, while "would" and "must" indicate certainty.

But ... it's most important that we replicate the flaw(s). If (E) seemed to contain the two flaws better than any other answer choice, then I'd still have to pick it, in spite of it having a weaker conclusion than the stimulus did.

But even though we can't eliminate B/D/E because of the language mismatch, it's still a great thought/habit to use that sort of shortcut to screen out B/D/E on your first pass.

We're all looking for ways to make Matching questions less time consuming and labor intensive, and being sensitive to conclusion language similarities can be a great way to zoom in on your likely answers without having to read all five choices.

Just don't force it based on a language match. If the reasoning pattern doesn't hold up, it doesn't save an answer for its conclusion to use identical wording.