The question stem reads: Which one of the following, if true, most weakens the argument? This is a weaken question.
The author describes two groups of people who have chronic trouble falling asleep. One group relies only on sleeping pills, while another relies only on behavior modification to treat their maladies. The group that relies on behavior modification falls asleep more quickly than the group that relies on sleeping pills. The author concludes from this that behavior modification is more effective than sleeping pills in helping people fall asleep.
The author has made the causal claim: the author argues that behavior modification is causing that group to fall asleep faster than the group who uses sleeping pills. In the curriculum, we covered how the tool science uses to identify causes is the Ideal Experiment. One of the requirements of the Ideal Experiment is that we randomly assign the samples into experimental and control groups. Random assignment of the groups helps isolate the hypothesized cause by controlling for other causes.
The author has provided the hypothesis that behavior modification is causing that group to fall asleep faster than the sleeping pill group. If this were an ideal experiment, we would expect to see a large sample size of people who had chronic trouble falling asleep assigned into a behavior modification group, a sleeping pill group, and a control group. However, what we find in the stimulus is not an experiment with randomly assigned groups. Instead, we find an observation that people who use behavior modification tend to fall asleep faster than those who use sleeping pills. By failing to assign groups randomly, we fail to isolate for other causes, such as self-selection. What does self-selection mean in this case? Let me ask you, “Why might it be that some people use sleeping pills (a medical intervention) and others use behavior modification (a change in habits)?” If you think that people who use sleeping pills might have a more severe case of insomnia than those who use behavior modification, you are spot on. The individuals who have a less severe case of insomnia might have simply self-selected into using behavior modification. The fact they fall asleep quicker might not be caused by their treatment. Instead, they simply have a less severe form of the disease.
Our job is to weaken the argument. So a good answer choice will illustrate the problem we just identified.
Answer Choice (A) is irrelevant to the argument. The argument is about the time it takes to fall asleep, while (A) speaks to the amount of sleep different groups get over the course of a night.
Answer Choice (B) fails to weaken the argument by comparing the behavioral modification group to a newly introduced group: one that has no trouble falling asleep. We can rule this answer choice out because the argument is solely concerned with individuals who need help falling asleep. The conclusion is a comparative claim between behavior modification and sleeping pills, so the comparison between behavior modification and people who do not have trouble falling asleep is irrelevant.
Answer Choice (C) fails to weaken because the argument is already explicitly concerned with the group that uses behavioral modification and does not use sleeping pills. Whether or not people have or have not used sleeping pills in the past is arbitrary.
Correct Answer Choice (D) is exactly what we prephrased. (D) States that the people who are most likely to use sleeping pills are those who have the most trouble falling asleep. So those who use sleeping pills could be falling asleep slower because they initially had much more trouble falling asleep than those who decided to use behavioral modification.
Answer Choice (E) is incorrect. While it does expose a self-selection bias (Those who choose the behavior modification prefer it to medication), it is unclear exactly how that would affect the time it takes to go to sleep. (D) provides a much clearer reason as to why the pill group takes longer.
Cookie Cutters
39.2.05
25.4.24
The Question Stem reads: The lawyer's conclusion follows logically if which one of the following is assumed? This is a Sufficient Assumption question.
The lawyer begins by describing how this witness was present at the restaurant when the lawyer's famous client was assaulted. However, the witness claims to recognize the assailant but not the famous client. The lawyer concludes the witness's testimony should be excluded. We can break down the argument to read:
P1: Witness claims to recognize the assailant
P2: Witness claims not to recognize the victim (Famous client)
________________
C: Exclude witness testimony
In the CC, we discussed that elements of the conclusion must be in the premises. Nowhere in the premises do we see a claim about what kind of testimony should not be included. We need a conditional that brings us to "exclude testimony," so let's make that our necessary condition: (__) -> Exclude testimony.
Now it will be hard to anticipate what sufficient condition the AC will use. They could use P1 or P2 or some combination of both. When we screen these answer choices, the first order of business will be to make sure that the necessary condition is: "exclude testimony" Then we will check the sufficient condition to ensure it gets triggered by the information in the stimulus. Let's go.
Answer Choice (A) has the necessary condition "then the witness's testimony should be included." Without looking at the rest of the (A), we can eliminate it because it takes us to "include" when we want to go to "exclude." If you picked (A), you likely assumed that "claims recognize both parties -> include" implied that "/(claims recognize both parties) -> exclude," which is a logical fallacy. Remember: a->b does not imply /a->/b.
Answer Choice (B) is arbitrary. Why would the fact that other witnesses can identify the client mean we should exclude the witness from the stimulus? Nothing. Eliminate and move on.
Answer Choice (C) is also arbitrary because it does not bring us to a conclusion "exclude testimony." As a side note, whether or not we can know if the witness actually recognized the assailant is irrelevant. Notice how the premises only take into account who the victim claims to recognize. The lawyer's argument is going to rely on the witness's claims, not what actually is the case.
Correct Answer Choice (D) gets us to where we need to go. If we take the contrapositive of (D), we get: "/(claims to recognize both parties in assault) -> exclude." The necessary condition is exactly what we discussed. The sufficient condition is great. The witness did not claim to recognize both parties in the assault. The witness claims to recognize only the assailant. So the conditional triggers and delivers us to the conclusion that the witness's testimony should be excluded.
Answer Choice (E) is a popular wrong answer. If you picked (E), you likely inferred that the witness was lying about not recognizing the famous victim. First, that is not an inference you can make. Just because it is unlikely that someone wouldn't recognize the famous client, that does not mean it is impossible that someone would fail to recognize the client. Second, even if we could infer that the witness was lying, it wouldn't help us. What does lying have to do with excluding testimony? If you answered that "liars testimony should be excluded," you've proved that (E) by itself is insufficient to draw the lawyer's argument.
The question stem reads: The biologist’s argument is most vulnerable to criticism on which one of the following grounds? This is a Flaw question.
The biologist begins by describing how many paleontologists suggest that the difficulties of the ice age were a cause of the evolution of the human brain. The biologist concludes those palentologists are wrong. In other words, the ice age was not responsible for the evolution of the human brain. As evidence, the biologist cites that many animal species survived the ice age with no evolutionary changes to their brain.
The biologist has hypothesized that the ice age was not repsonsbile for the evolution of the human brain. If we were to construct an ideal experiment to test this hypothesis, what kind of subjects would you want to use? You would want to use human brains! However, the biologist instead uses animals brains as evidence. The question is, “Are humans and animals” the same? Maybe. Maybe not. The biologist’s argument relies on the assumption that humans and animals would respond to the evolutionary pressures of the ice age in the same way. So let’s look for an answer choice that distinguishes how animal brains and human brains would respond to the ice age.
Answer Choice (A) is incorrect. The biologist does not suggest that the ice age was sufficient or necessary to produce brain evolution in humans or animals.
Correct Answer Choice (B) draws the distinction between humans and animals that we are looking for. The biologist fails to consider the possibility that the ice age could have produced the evolution of the brain in humans without producing the evolution of the brain in other species.
Answer Choice (C) is incorrect. The argument is not about whether the ice age was necessary for producing changes in the brains of humans or animals. The argument is about whether the ice age was sufficient to bring about changes in the brains of humans and animals.
Answer Choice (D) is incorrect. The biologist never presumes that humans had a more difficult time during the ice age than animals.
Answer Choice (E) is incorrect. The biologist does not presume that the ice age was causally responsible for the evolution of human brains. He concludes that the ice age was not casusualy responsible for the evolution of human brains.
The arrival of television in North America did not lead to a decline in new book publications or in book sales.
An increase in new books sold each year does not always coincide with an increase in library circulation.
A
Television has, over the years, brought about a reduction in the amount of per capita reading in North America.
B
The introduction of television usually brings about a decrease in library use.
C
Book publishers in North America now sell fewer copies per title than they sold in the early days of television.
D
The availability of television does not always cause a decline in the annual number of book titles published or in the number of books sold.
E
The introduction of television expanded the market for books in North America.
A
Child-rearing books should encourage people with children to put poinsettias in their homes.
B
Poinsettias are not dangerously poisonous.
C
According to many child-rearing books, poinsettias are dangerous.
D
The belief that households with children or pets should not have poinsettias is mistaken.
E
Poinsettias pose no risk to children or pets.
News media are more likely to report on rare or unusual threats to life than on common threats.
People who estimate risk based on news reports likely underestimate the risk of common threats and overestimate the risk of rare or unusual threats.
A
Whether governmental action will be taken to lessen a common risk depends primarily on the prominence given to the risk by the news media.
B
People tend to magnify the risk of a threat if the threat seems particularly dreadful or if those who would be affected have no control over it.
C
Those who get their information primarily from the news media tend to overestimate the risk of uncommon threats relative to the risk of common threats.
D
Reporters tend not to seek out information about long-range future threats but to concentrate their attention on the immediate past and future.
E
The resources that are spent on avoiding product tampering are greater than the resources that are spent on avoiding threats that stem from the weather.
The question stem reads: The argument is most vulnerable to criticism on which one of the following grounds? This is a Flaw question.
The author begins by stating how many parents organize their child's playtime in order to enhance their child's cognitive development. The author concludes that the parents' belief is incorrect: Organizing a child's playtime will not enhance cognitive development. To prove their claim, the author says, "To thoroughly structure a child's playtime and expect this to produce a creative and resourceful child would be like expecting a good novel to be produced by someone who was told exactly what the plot and characters must be."
What a minute. Is producing "a creative and resourceful child" the reason parents organize playtime? All we know is that the parents organized play time to enhance cognitive development. Creativity and resourcefulness are a subset of cognitive functions. So there could be cognitive functions the parents want to enhance besides creativity and resourcefulness. Perhaps the parents organize playtime to improve a child's ability to organize. Shocking! So the author has failed to consider that organized playtime might enhance cognitive development in areas besides creativity and resourcefulness.
Answer Choice (A) is incorrect. The author wants to say organized playtime is not conducive to enhancing cognitive development. (A) would look better if it said, "Takes for granted that if something (organized playtime is not conducive to a certain goal (developing creativity and resourcefulness), it also cannot be conducive to some other goal (enhancing cognitive development).
Answer Choice (B) is overlooked by the argument but is also irrelevant. Whether or not children enjoy organized playtime is arbitrary.
Answer Choice (C) is also incorrect. The author never considers organized playtime to be necessary for enhancing a child's creativity and resourcefulness.
Answer Choice (D) has nothing to do with the argument. The author never actually says writing a good novel requires creativity and resourcefulness. The author claims you can't expect a good book to be written by someone who is told what characters and plot to use.
Correct Answer Choice (E) is what we discussed. The author does fail to consider that organized playtime could enhance other aspects of cognitive development (which would improve overall cognitive development) without enhancing creativity and resourcefulness.