#7 - To become an expert on a musical instrument, a person

[Administrator]

Complete Question Explanation

Flaw in the reasoning-SN. The correct answer choice is (B)

This stimulus provides a conditional argument. The diagram of the premise is as follows:

• 3+ hours practice expert

The stimulus then concludes:

• Expert practice 3+ hours.

This reasoning represents a mistaken reversal. As a general tip, mistakes in sufficient-necessary arguments are often described generally as "mistakes a sufficient for a necessary condition (or the vice versa); ignores the possibility that one way to do something is not the only way to do it, etc. Or the answer choice may be more specifically tailored to the stimulus: ignores the possibility that one can become an expert without practicing 3+ hours, etc. These would all represent acceptable pre-phrases.

Answer choice (A) The stimulus clearly states that if one practices for 3+ hours a day, one will be considered an expert; thus, it can be said that the stimulus' conclusion has taken this into account.

Answer choice (B): This is the correct answer choice. This matches our pre-phrase that one can become an expert without practicing 3+ hours a day. This answer choice suggests the same thing—that some people can become experts by practicing less than 3+ hours.

Answer choice (C) This is the contrapositive of the stimulus' conclusion—that IF NOT 3+ hours, THEN NOT expert. The conclusion itself makes this very argument, so it cannot be said that the conclusion fails to take this into account.

Answer choice (D) This choice introduces new elements of three consecutive hours (the stimulus only deals with 3+ hours in general), and recommendation by music teachers (which the stimulus does not mention at all).

Answer choice (E) Again, in this answer choice, new elements are introduced—the lack of spare time.

[rameday]

Hello,

So i have come across a few flaw questions that are very sneaky with respect to how they explain a MN and MR in the AC's.


My prephrase for this question was MR and look for conditional language. However none of the answers had that. The correct answer disguised the MR using the specifics of the question. I am a bit confused as to how the answer B is actually explaining a MR. I get that a MN takes the non existence of something as evidence that the necessary precondition does not exist. I also get that a MR is confuses what is necessary with being sufficient. Just not sure how that spirit is embodied within answer B.

[Nikki Siclunov]

Hi rameday,

You are absolutely correct in that not all Flaw questions in stimuli with conditional reasoning errors will use the terms "sufficient" and "necessary" to describe the flaws. They often do, but need not to: an error in conditional reasoning can also be described with language using the specifics of the question.

Let's take the argument in Question 2, page 7-29:

Premise: Practice for 3 hrs/day Expert
Conclusion: Expert Practice for 3 hrs/day

Clearly, the conclusion is a Mistaken Reversal of the premise. It is imperative to understand precisely why the Mistaken Reversal is actually a logical fallacy: it presumes that just because a certain type of practice (min. 3 hrs/day) is sufficient to establish a desired result (becoming an expert) that this type of practice is necessary for the result. In other words, the author ignores the possibility that there are other ways to become an expert. The correct answer choice can state any of the following:

The author presumes without warrant that just because a certain type of practice is sufficient to achieve a desired result that this type of practice is a necessary precondition for achieving that result.

The author assumes, without justification, that practicing for 3 hours a day is the only way to become an expert.

The author ignores the possibility that practicing for less than 3 hours a day may be enough for some people to become experts.

The conclusion fails to take into account that practicing for 3 hrs a day is not the only way for some people to become experts.

As you can see, certain keyword identification strategies in Flaw questions that contain errors in conditional reasoning may not always work: test makers have learned how to describe such errors without the use of the requisite keywords (e.g. “necessary,” “sufficient,” etc.). Indeed, you should assume that test-makers are always two steps ahead of you when it comes to such shortcuts, and have designed strategies meant to circumvent their utility or applicability. Check out the following blog posts on this topic:

http://blog.powerscore.com/lsat/bid/153 ... n-the-LSAT

http://blog.powerscore.com/lsat/bid/312 ... f-keywords

Hope this helps!

[Johnclem]

Hi,
I completely understand why the correct answer is the correct answer . but I just have some questions in regards to the conditions presented in the stimulus. There's a change from practicing to practicing 3 hours a day. Am I to treat premise one as a repeat statement of the conclusion or is there an error in language shift .?

1) Expert --> Practice
2) practice 3hrs--> expert
C: expert --> 3hrs/day

Thank you
John

[Clay Cooper]

Hi Johnclem,

Thanks for your question. You should treat the first premise and the conclusion as different statements, because they are; that is where the error comes in in this question.

Premise one tells us for certain that experts practice.

The conclusion claims that experts practice more than three hours a day.

These are not the same statement. Under the first, I could practice an hour a day and still potentially attain expertise; whereas, if the conclusion were true, that would be impossible.

It is an error of conditional reasoning (as discussed in the explanation above) and that is why it is incorrect; the shift in language is not a minor or unimportant one.

I hope that helps.

[lathlee]

For the record, Dave and other amazing team members, as I made clear, I write the LSAT test in special circumstance so I write tomorrow for Sep LSAT.

Anyways, I got this question wrong twice and looking over the questions wrong why I got wrong to prepare for tomorrow. I think this might be the better way to explain: In question stem, we know that sufficient condition and necessary condition; then introduces necessary conclusion occurred but a necessary conclusion can occur without the sufficient condition regardless.

as in of necessary condition of " Expert" can occur with or without practice. The people who have complained about this question seems to have a difficult time, seems to forget the NORMAL Setting, not contrapositive setting of SN relationship operate in first place.

[Adam Tyson]

We are looking forward to hearing how you did, lathlee! Sorry we were not able to respond to this post before the test, but we were swamped at the last minute, and even with half a dozen or so instructors tackling the questions last Thursday and Friday we did not manage to get to every one of them. Looking at it now, you are absolutely correct in your analysis here - good work! I hope that level of analysis and confidence carried you through to victory this past weekend!

[lathlee]

I already corrected the mistake. but anyways, the previous comment one, I should have said, this might be a better way to explain this

[Mastering_LSAT]

Hi there,

I just wanted confirm my understanding as to why (A) is incorrect. Would greatly appreciate your help with this.

When we keep in mind that our task on this question is to describe a flaw in the reasoning, then we see that the answer choice (A) neither describes the flaw in the argument’s reasoning, nor correctly describes the argument’s conclusion.

Answer choice (A) states that “[t]he conclusion fails to take into account that people who practice for three hours every day might not yet have reached a degree of proficiency that everyone would consider expert.”

First, the argument’s conclusion, actually, does take the mentioned fact in answer choice (A) into account. The argument’s conclusion is that becoming an expert requires practicing for at least three hours each day. This means that satisfying the necessary condition in the conclusion (practicing for at least three hours per day) may or may not lead to the sufficient condition being present (someone becoming an expert). In sum, the argument’s conclusion in and by itself DOES take into account that 3+ hours of practice does not guarantee someone becoming an expert.

Second, if what answer choice (A) suggests is a flaw, then the argument’s conclusion would have to repeat one of the argument’s premises to rectify it. In such a case, the argument’s conclusion would look something like: 3+ hours of practice is enough to become an expert on a musical instrument, or, alternatively, someone is an expert on a musical instrument if and only if the person is practicing for 3+ hours per day on that instrument. But wait a second… The argument’s conclusion should give us a new, previously unknown, piece of information based on the known information in the premises. When the argument’s conclusion repeats one of the premises, the argument commits a flaw of circular reasoning. Again, if what answer choice (A) suggested was a flaw, then, to correct it, we would have to commit a fallacy of circular reasoning.

Lastly, the answer choice (A) does not address the actual flaw in the reasoning, which is a mistaken reversal.

Does my reasoning as to why (A) is incorrect valid? Am I missing anything?

Many thanks for your help!

[Robert Carroll]

Mastering_LSAT,

Sounds like good analysis to me!

Robert Carroll