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Complete Question Explanation

Parallel Flaw-CE. The correct answer choice is (C)

This Parallel question uses causal reasoning, but concludes that the cause does not work. Antitheft devices do not have their intended cause of deterring theft. We should first look for an answer that involves causal reasoning and concludes that the cause does not produce the intended effect.

Answer choice (A): Although this answer choice seems to involve causal reasoning, it does not conclude that a cause does not produce an intended effect based on these surveys. Its conclusion does not match the stimulus's conclusion at all.

Answer choice (B): There does not appear to be any cause and effect reasoning in this answer choice. The conclusion is about who the library is intended to serve based on its collection. We do not know if this intention is successful or not (which is what the conclusion of the stimulus concerns). Again, if you Double the Conclusion, you will see that this conclusion does not match.

Answer choice (C): This is the correct answer choice, as it follows the pattern of reasoning present in the stimulus. It presents a study (notice that the parts of the argument need to match — the stimulus presents statistics) that seems to contradict common sense. Then, it concludes that one effect libraries may be intended or thought to produce does not occur.

Answer choice (D): The conclusion here: ("children who do not like to read usually have perfect vision") besides being ridiculous, does not match the "do not protect" of the stimulus at all. Although this is extremely flawed reasoning, it does not match the reasoning of the stimulus.

Answer choice (E): This answer choice postulates a cause and effect relationship, but it never claims that an intended or commonsense effect does not occur like the conclusion of the stimulus does.
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I'm still a bit confused on this question; I interpreted the flaw as being a confusion of causation and correlation; maybe cars with auto-theft devices are stolen more, which seems more in line with D or E.
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Hi halincadenza,

You're right that the author is confusing correlation and causation. In the example in the prompt, he reasons that since cars with antitheft devices are more likely to be stolen, the antitheft devices don't work. He's failing to take into account the fact that these two factors are actually both effects of a single cause: expensive cars are both more likely to have antitheft devices and more likely to be targeted by car thieves. The cause (owning an expensive car) produces both effects (installing an anti-theft device in the car and having the car stolen).

Answer choice (C) mirrors this reasoning. The author says that people who use libraries frequently are also more likely to buy a lot of books. He then concludes on this basis that using libraries doesn't reduce the number of books an individual buys. The flaw is that he's missing the independent cause behind both factors: individuals who both use libraries frequently and purchase books are probably bookworms who just read a lot more than everyone else. An independent cause (being a bookworm) is producing both effects (using the library frequently and buying lots of books).

Answer choice (D) doesn't parallel the flaw in the stimulus because answer choice (D) is actually an example of accurate reasoning.

Answer choice (E) also depends on causal reasoning, but unlike in the stimulus it doesn't fail to account for an obvious alternate cause that produce the effect of both supporting free libraries and free universities.
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I got this question right, but I had a lot of trouble prephrasing the answer. I saw many problems with the stim-- maybe the cars with the antitheft devices are left in more dangerous areas. Maybe there are just more cars with antitheft devices, so more get stolen. Maybe more cars with antitheft are stolen, but even more would be if they didn't have antitheft. Because there were so many issues with the stim, I had a lot of trouble distilling the flaw and prephrasing it. I eventually awkwardly took the "maybe even more cars would be stolen without antitheft" error and translated it to "maybe regular library users would purchase even more books without libraries". I got the question right, but compared with the above prephrase, it was a lot harder than it needed to be. How did you make such a simple but effective prephrase?
 Adam Tyson
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It can be helpful sometimes to approach Flaw questions like Weaken questions, Tajadas. If you go on the attack, you will be identifying and taking advantage of the Flaw. Here, your last prephrase turns out to be a great Weaken answer - what if those cars with antitheft devices would have been stolen even more without those devices? What this prephrase does is contradict the conclusion: they say the devices don't help, and you respond with "well what if they DO help?"

From there you are just a short step away from identify the flaw, which is that the argument fails to consider that maybe the devices are helping, that maybe things would have been even worse without them. Failing to acknowledge the weakness in the argument is a good way to describe just about any flaw!

Think about simply contradicting the conclusion in the stimulus, and you are going to find yourself very close to having a great prephrase for a Weaken or Flaw question. Don't overthink it - just think "nope, you're wrong" and go from there!

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