Section Types Logical Reasoning

LSAT 145 - Section 4 - Question 19

January 31, 2016

Studies have shown that pedestrians are struck by cars when crossing streets in crosswalks more often than they are struck when crossing outside of crosswalks. This is because crosswalks give many pedestrians an overly strong sense of security that oncoming cars will follow the signals, and these pedestrians are less likely to look both ways before crossing the street.

Summarize Argument: Phenomenon-Hypothesis

The author hypothesizes that pedestrians feel too safe in crosswalks and don’t watch for oncoming cars. To support his hypothesis, he notes a correlation: pedestrians get hit by cars more often when crossing at crosswalks than when crossing anywhere else.

Notable Assumptions

Based on a mere correlation, the author concludes that the cause of increased accidents in crosswalks must be because pedestrians behave less safely when crossing there. But there could be other possible causes that would explain why more pedestrians get hit in crosswalks. Perhaps there are simply many more pedestrians crossing at crosswalks than anywhere else, and so more accidents occur there. Or perhaps it’s not the pedestrians who get careless in crosswalks, but the drivers. The author assumes these alternative explanations aren’t true.

A

The overwhelming majority of pedestrians in high-traffic areas cross streets in crosswalks.

This is a good alternative explanation for why more pedestrians get hit in crosswalks: that’s just where most pedestrians cross! If this is true, the author’s explanation is weakened—we have less reason to think that pedestrians are being especially unsafe in crosswalks.

B

The number of pedestrians struck by cars has increased in recent years.

This compares the number of pedestrians getting hit by cars everywhere over time. That’s the wrong comparison. We need to understand why more pedestrians are hit in one place (crosswalks) than any other place at a given time.

C

Pedestrians tend to underestimate the chances that the signals at a crosswalk will malfunction.

Too many unknowns. We have no idea how often this happens, or what the safety effects of this are. Perhaps this only causes a negligible uptick in pedestrians being struck by cars. Or perhaps this actually reduces accidents, because the signal’s stuck on “don’t walk”!

D

Drivers are generally most alert to pedestrians who are in or near crosswalks.

This strengthens the author's explanation by eliminating the alternative hypothesis that drivers are the careless ones rather than pedestrians.

E

Measures intended to promote safety tend to make people less cautious.

Crosswalks are one such measure. This supports the author’s argument.

28 comments

LSAT 77 - Section 4 - Question 18

January 31, 2016

1 comment

LSAT 145 - Section 4 - Question 18

January 31, 2016

Psychologist: Phonemic awareness, or the knowledge that spoken language can be broken into component sounds, is essential for learning to read an alphabetic language. But one also needs to learn how sounds are symbolically represented by means of letters; otherwise, phonemic awareness will not translate into the ability to read an alphabetic language. Yet many children who are taught by the whole-language method, which emphasizes the ways words sound, learn to read alphabetic languages.

Summary

In order to read an alphabetic language, one must have phonemic awareness and have learned how sounds are symbolically represented by means of letters.

Many children who are taught using the whole-language method learn to read alphabetic languages.

Very Strongly Supported Conclusions

Many children who are taught using the whole-language method have phonemic awareness and have learned how sounds are symbolically represented by means of letters. (This must be true, because many children who are taught using the whole-language method can read an alphabetic language, which implies that they have what’s required to read an alphabetic language.)

A

The whole-language method invariably succeeds in teaching awareness of how spoken language can be broken into component sounds.

We don’t know whether the whole-language method is ever successful in teaching how spoken language can be broken into component sounds. We know that many children who are taught using this method can learn how spoken language is broken into component sounds, but we don’t know whether they learned this from the whole-language method.

B

When the whole-language method succeeds in teaching someone how to represent sounds by means of letters, that person acquires the ability to read an alphabetic language.

We know that learning how sounds are represented by means of letters is one necessary condition for reading an alphabetic language. But we don’t know that it’s sufficient. In fact, phonemic awareness is another requirement, so if someone doesn’t have phonemic awareness, they won’t be able to read, even if they understand how sounds are represented by letters.

C

Those unable to read an alphabetic language lack both phonemic awareness and the knowledge of how sounds are symbolically represented.

Not supported, because someone who can’t read an alphabetic language might be lacking some other necessary condition that we don’t know about. It’s possible they have phonemic awareness and knowledge of how sounds are represented by letters, but still can’t read for some unknown other reason.

D

Some children who are taught by the whole-language method are not prevented from learning how sounds are represented by means of letters.

Must be true, becaue we know many children taught using the whole-language method can read alphabetic languages. So they must understand how sounds are represented by means of letters.

E

The whole-language method succeeds in teaching many children how to represent sounds symbolically by means of letters.

Not supported, because we don’t know that the whole-language method is how many children who learn to read alphabetic languages came to understand how sounds are represented by letters. It’s possible that they learned this through something else besides the whole-language method. In other words, just because they were taught using the whole-language method does not imply that this method is how they learned what’s necessary to read alphabetic languages.

27 comments

LSAT 77 - Section 4 - Question 17

January 31, 2016

8 comments

LSAT 145 - Section 4 - Question 17

January 31, 2016

12 comments

LSAT 77 - Section 4 - Question 16

January 31, 2016

13 comments

LSAT 145 - Section 4 - Question 16

January 31, 2016

Researcher: Dinosaurs lack turbinates—nasal cavity bone structures in warm-blooded species that minimize water loss during breathing. According to some paleobiologists, this implies that all dinosaurs were cold-blooded. These paleobiologists must be mistaken, however, for fossil records show that some dinosaur species lived in Australia and Alaska, where temperatures drop below freezing. Only warm-blooded animals could survive such temperatures.

Summarize Argument: Counter-Position

The author rejects the paleobiologists’ belief that all dinosaurs were cold-blooded. Since some dinosaurs lived in places where only warm-blooded animals could survive, the author implies that some dinosaurs must have been warm-blooded.

Identify Argument Part

It’s a premise. The author uses the claim that only warm-blooded animals could survive in those areas to prove that the dinosaurs that lived in those areas were not cold-blooded.

A

It is presented as a potential counterexample to the argument’s main conclusion.

The last sentence supports the conclusion, so it can’t be a counter-example to it.

B

It is a premise offered in support of the argument’s main conclusion.

This accurately describes the role of the last sentence. It’s a premise supporting the author’s conclusion.

C

It is presented as counterevidence to the paleobiologists’ assertion that dinosaurs lack turbinates.

The author never suggests that dinosaurs actually have turbinates. The claim that the author counters is the paleobiologists’ claim that all dinosaurs were cold-blooded.

D

It is the argument’s main conclusion.

The main conclusion is the claim that the paleobiologists are wrong. The last sentence supports that conclusion.

E

It is an intermediate conclusion for which the claim that some dinosaur species lived in Australia and Alaska is offered as support.

The claim that some dinosaurs lived in Australia and Alaska isn’t offered to help prove that only warm-blooded animals can live in freezing temperatures.

17 comments

LSAT 77 - Section 4 - Question 15

January 31, 2016

14 comments

LSAT 145 - Section 4 - Question 15

January 31, 2016

Outsiders in any field often believe that they can bring in fresh, useful solutions that have been overlooked by insiders. But in fact, attempts at creativity that are not grounded in relevant experience are futile. Problems can be solved only by people who really understand them, and no one gains such understanding without experience.

Summary

Outsiders believe they can provide new solutions in fields they are unfamiliar with, but they are wrong. Creativity without relevant experience is useless. Effective problem-solving requires a deep understanding of the problems, which is gained through experience.

Strongly Supported Conclusions

Problem-solving requires experience (or any valid inference along this chain)
Problem solved —> have understanding —> experience in the field.

A

The more experience a person has in a field, the more creatively that person can solve problems in the field.

The stimulus does not say that more experience leads to more creativity. It only argues that creativity without experience is useless.

B

Those people who are experienced in a field rarely overlook creative solutions.

This is too strong to support. The stimulus argues that only experienced individuals can provide creative solutions, not that they always possess creative solutions.

C

Creative solutions in a field always come from people with experience in that field.

The stimulus explains that creativity without experience is useless, and problems can be solved only by people who understand them. Thus, creative solutions must come from people with experience.

D

The experience required for effective problem-solving in a field does not vary depending on the field’s complexity.

The stimulus does not mention whether experience differs based on the field’s complexity. You must make a number of assumptions to make this work.

E

Outsiders should be properly trained in a field before being given responsibility in that field.

The stimulus does not say anything about when to give outsiders responsibility. The stimulus is purely focused on the requirements to come up with creative solutions.

15 comments

LSAT 77 - Section 4 - Question 14

January 31, 2016

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