We should recognize this as a strengthening question, since it asks us: Which one of the following, if true, would most support the researcher’s hypothesis?
We should know right from the get go that we are dealing with a strengthening question that involves a hypothesis, just based off of the question stem. As a reminder, whenever our conclusion is a hypothesis, an answer choice which eliminates an alternate hypothesis will always strengthen our argument. As we read our stimulus, we should be on the lookout for what it is our hypothesis is trying to explain; what is our phenomenon?
Our stimulus begins with essentially a definition of pit vipers; they are vipers with pits on the sides of their head which give them a thermal (think heat) impression of their environment. Interesting! This is our phenomenon; pit vipers have infrared sensors. We next learn about a prior hypothesis, an explanation for why this is the case. Scientists used to believe that the explanation for why pit vipers have their pits is that it helps them find prey, because all pit vipers are predators. However, the hypothesis we are tasked with supporting is that of a researcher who believes the pits are actually for detecting the pit viper’s predators.
What we have to remember is that predator and prey, similar to premise and conclusion, are relata. Just as the same sentence can be both a premise and a conclusion relative to other parts of the same argument, an animal can both be prey (relative to its predators) and a predator (relative to its prey). So although the scientists were right that all pit vipers are predators, they forgot that they are also all prey! So we now have two explanations for why the pit vipers have pits which have equivalent support. Our job is to tip the scales in favor of the detecting predators hypothesis. Let’s see what we get:
Answer Choice (A) This gives us a comparative of the pit viper genders which tells us none of their differences, but only traits they both share. We already knew they had infrared sensors, so all we learn is that they exhibit both aggressive and defensive behavior. The problem is that this could both support that the pits are for spotting prey (aggressive) or for evading predators (defensive), and in either case the support is incredibly small.
Correct Answer Choice (B) This is what we would expect to be true if the pits were for evading predators and not for finding prey! What this answer essential gives us is a correlation; having pits correlates with markedly different defense strategies. It also gives us the absence of a correlation between having pits and different predatory behavior. This tips the scale in favor of our avoiding predators hypothesis!
Answer Choice (C) But why do they have the pits!
Answer Choice (D) Interesting, but this does nothing to explain why they might have the pits, and whether it relates to avoiding predators.
Answer Choice (E) C, D, and E all introduce some new factor (venom, smell, and rattles) without giving us any information that could support that pit vipers have their pits to avoid predators.
This is a weakening question: Which one of the following, if true, most seriously undermines the conclusion above?
Our stimulus begins by telling us that surgery was restricted to emergencies only following a relatively high mortality rate in area hospitals. Sounds like a smart decision! It seems the plan worked, and deaths fell by almost a third during the period of restriction. Unfortunately however, when non-emergency surgeries were allowed to resume, the death rate rose again. From all of this the argument concludes that the risks of elective (i.e non-emergency) surgery had been often unnecessarily incurred in the area. In other words, people were risking their lives in surgeries that they didn’t really need. We should notice that although our support does give us good evidence that people were dying, we haven’t established whether or not these risks were necessary. We are assuming that just because a surgery wasn’t an emergency, well then it wasn’t a necessary risk. Our job on this question is to weaken this conclusion that the deaths were due to unnecessary surgeries. Let’s see what our answers have to offer:
Correct Answer Choice (A) This weakens the conclusion by assigning a reason for the elective surgeries which would make possible mortality a necessary risk even if the surgery wasn’t an outright emergency. Sure these weren’t car accident victims who were going to immediately die without surgical intervention, but every day they delayed the surgery their chances of surviving just got worse; it was necessary to perform the surgeries sooner rather than later.
Answer Choice (B) The conclusion is that the risks were incurred unnecessarily, not unknowingly.
Answer Choice (C) This would if anything strengthen the argument by suggesting the surgeries were being unnecessarily performed.
Answer Choice (D) It is entirely consistent for elective surgeries to be, in general, less risky than emergency surgeries, and for hospitals in the area to be incurring unnecessary risks performing said surgeries.
Answer Choice (E) This doesn’t address the argument, it just distinguishes surgery failure from surgery mortality.
This is a weakening question, indicated by: Which one of the following, if true, undermines the conclusion concerning words for colors?
The stimulus begins with the fact that many languages have distinct words for the brother of your mother and the brother of your father, while in English both are referred to as “uncle”. The next sentence concludes that this is evidence of a more finely discriminated kinship system than that of English speakers. Basically, those cultures care more about the minutia of family than English-speaking cultures. We then get another premise, informing us that basic words for colors vary between languages, followed by another conclusion that speakers of languages with fewer words for color must be unable to distinguish as many colors as speakers of English. What a bad argument! The reasoning however is pretty clear; both arguments infer that a difference in language reflects a difference in reality. We’re specifically told which of the conclusion we are to weaken in the question stem, so we should look for an answer choice which would make the color conclusion significantly less likely to be true. Let’s see our options:
Correct Answer Choice (A) This gives us a case where one group is able to distinguish colors but only has one word, directly weakening the argument’s reasoning that number of words and distinguished colors are one to one.
Answer Choice (B) This is completely consistent with the conclusion being true.
Answer Choice (C) This seems to suggest they do distinguish colors differently from English speakers; while unripe bananas are green, I haven’t seen many blue leaves!
Answer Choice (D) This adds nothing.
Answer Choice (E) This is completely consistent with the conclusion being true.
Here we have a weakening question, as the stem asks us: The charge made above against alternative medicine is most seriously weakened if it is true that
The question begins with the claim that orthodox medicine is ineffective at both ends of the spectrum of ailments. Orthodox in this context just means ‘standard’. This claim is elaborated with the details that orthodox medicine is bad at dealing with both minor discomfort and serious life-threatening illnesses. So standard medical practice can’t do much for your toothache or your tumor, if your problem is mild they can’t treat symptoms and if it’s severe they can’t cure it. For this reason, people turn to alternative medicine because orthodox medicine fails them or produces unwanted side effects. But alternative medicine has less unwanted side effects partly because it doesn’t have any effects at all. Doesn’t sound like it’s going to do any better of a job! Our task is to weaken this conclusion that alternative medicine doesn’t have any positive or negative effects. Let’s see our answer choices:
Answer Choice (A) This doesn’t have anything to do with effects.
Answer Choice (B) So they have different ideas about medicine, I think we could have gotten that from the ‘alternative’ part.
Answer Choice (C) That’s nice for the patient and could maybe be construed as an effect (though only for the subset whom orthodox medicine couldn’t cure), but this is a much weaker answer than D.
Correct Answer Choice (D) This suggests that alternative medicine can have side effects!
Answer Choice (E) Our job is to weaken the conclusion that alternative medicine has no side effects, we don’t care about orthodox medicine’s effects!
We should recognize this as a strengthening question, since the stem states: Which one of the following, if true, most strengthens the teacher’s argument?
Our stimulus takes the form of a dialogue between a student and teacher, and we are tasked with strengthening the teacher’s argument.
The teacher argues that journalists who don’t disclose the identity of their source stake their reputation on the ‘logic of anecdotes’. Basically, you judge their reporting, and consequently their reputation, on a similar basis to how you judge an anecdote. He supports this claim with some more specific information comparing anonymously sourced reports and anecdotes. It is necessary for an anonymous report to be published, and an anecdote to be good, that they be highly plausible, original, or interesting. The student responds by saying that if this were true, journalists wouldn’t need actual sources, since it wouldn’t be hard for a resourceful journalist to just invent plausible, original, or interesting stories. We want to support the Teacher’s claim that journalist stake their reputation on the logic of anecdotes when they use anonymous sources. On to the answer choices:
Correct Answer Choice (A) This connects our journalists premise about the requirements to be published with his conclusion about reputation.
Answer Choice (B) Our teacher’s argument is about anonymous sources; this isn’t relevant.
Answer Choice (C) This wouldn’t affect whether they get published, and hence whether the journalist stakes his reputation.
Answer Choice (D) This does nothing for us.
Answer Choice (E) We are interested in their reputation, and whether they stake it, not whether they are valued by their publishers.
This is a flaw/descriptive-weakening question and we know this because of the question stem: The reasoning above is flawed because it...
The argument starts out by giving us a reason for why typed passwords are a security risk because they’re easy to guess or steal. There is a new system that relies on voice authentication and in a trial, we’re told that the system never gave access to someone who wasn’t supposed to have access; in other words, it kept unauthorized users out. The argument concludes that if this result above can be repeated, then there will be a way to give access to authorized people and no one else.
This kind of error pops up now and again on the LSAT. It’s basically a confusing granting access and refusing access, and how many times it does each correct. In other words, if the system denies someone who isn’t supposed to have access every single time, that doesn’t mean that the system grants access to the people who are allowed access.
Answer Choice (A) is not descriptively accurate because the comparison is not faulty. The author says that typed passwords can be taken, but someone’s voice can’t be stolen. This is out.
Answer Choice (B) is trying to be a sample size flaw - and while it is descriptively accurate, it’s not a flaw. How big does the sample size need to be for this “general” conclusion, assuming that the conclusion that “voice recognition will work” is a general conclusion in the first place.
Answer Choice (C) is descriptively accurate but it’s not a flaw. It’s just additional information on the usefulness of this feature.
Correct Answer Choice (D) is descriptively accurate and it is the flaw. While you’re not giving access to unauthorized users, what about the accuracy of giving access to people who are authorized? We need to know this latter statistic before we make the conclusion.
Answer Choice (E) is not descriptively accurate; there is nothing to suggest that the conclusion is “heavily” qualified in any way.