"Surprising" Phenomenon
Why have auto thefts dropped dramatically in cities where car owners have the antitheft device installed, even though only a small % of car owners in those cities have installed the device?
Objective
The correct answer should help explain how only a small proportion of cars being equipped with antitheft devices can still lead to a significant decrease in the car theft rate.
A
Car thieves will tend to be less cautious if they are unaware that a car they have stolen contains a homing beacon.
But there’s still only a small % of cars with the device. Car thieves might be less cautious if they don’t know about these devices, which might mean these thieves get caught, but how could this dramatically decrease overall theft rates?
B
Typically, the number of cars stolen in cities where the homing beacons are in use was below average before the device was used.
We’re trying to explain how theft rates could have decreased. Whether theft rates started below, at, or above the average theft rates for cities doesn’t explain how those rates could have declined dramatically.
C
Before the invention of the homing beacon, automobile thieves who stole cars containing antitheft devices were rarely apprehended.
Even if we interpret this answer as suggesting thieves today are more frequently apprehended, wouldn’t we expect only a small proportion of thieves to be caught, since the device is installed in only a small proportion of cars? How could this significantly decrease cars stolen?
D
A large proportion of stolen cars are stolen from people who do not live in the cities where they are stolen.
We know only a small % of cars have the device installed in the relevant cities. Whether thieves live in other cities doesn’t affect our expectation that a small % of cars with the device should have only a small impact on overall theft rate.
E
In most cities the majority of car thefts are committed by a few very experienced car thieves.
If only a few car thieves are responsible for a large portion of car thefts, catching only a few car thieves can lead to a dramatic decline in thefts. This is how the devices could decrease thefts significantly despite being in only a small % of cars.
Summarize Argument
The author concludes that cash gifts of gift cards are more highly valued by recipients than are gifts chosen for them by others. This is based on a study in which people were asked how much they would have been willing to pay for gifts chosen for them by others. People responded with amounts that were, on average, two-thirds the actual price of the gifts.
Notable Assumptions
The author assumes that the amount people state for how much they would have been willing to pay for a gift is an accurate measure of how much they value the gift.
A
The rate at which gifts are returned to retailers has been steadily increasing since the rate was first measured.
The increasing return rate has no clear impact on how much people value gifts chosen by others. If (A) does anything, it might support the idea that people prefer the cash equivalent of a gift over the gift.
B
Gifts of cash and gift cards currently represent only about 14 percent of all gift giving.
How often people give gifts of cash or gift cards has no clear impact on whether people value the cash equivalent more than a gift chosen by others. Perhaps people tend not to give cash or gift cards because it’s perceived as worse than giving someone else a gift?
C
People in the study would have been willing to pay more for gifts chosen for them by close friends and relatives than for gifts chosen for them by others.
This compares gifts chosen by close friends/relatives to gifts chosen by other kinds of people. But this comparison, which is between subsets of the “gifts chosen by others,” doesn’t affect the comparison between gifts chosen by others and cash/gift cards.
D
People are unwilling to sell gifts chosen for them by others unless offered about one and a half times the gift’s actual price.
This presents a competing method of determining how much people value a gift, which produces a conflicting result. If people are unwilling to sell a gift unless offered more than its actual price, that arguably suggests people value gifts more than the cash equivalent.
E
Most retailers require receipts before people can return gifts for refund or exchange.
Whether retailers require receipts has no clear impact on the comparison between gifts and cash/gift cards.
Summary
Creating secure passwords for confidential computer files is difficult. Users prefer passwords that are easy to remember. Unfortunately, these passwords are the easiest to guess for an outsider. Random configurations of letters and numbers are the hardest for an outsider to guess, but also the easiest for a legitimate user to forget. Furthermore, passwords that are very difficult to remember are generally written down, and hence pose the greatest security threat of all.
Notable Valid Inferences
Passwords that are easy for an outsider to guess have less of a security threat than passwords that are very difficult to remember.
A
Computer users should not write down their passwords even if the passwords are hard to remember.
Could be false. The stimulus does not state a value judgement about what users should not do. We know that written passwords pose the greatest security threat, but it is possible there are other reasons to write passwords that outweigh these risks.
B
It is expensive to have system administrators constantly resetting forgetful users’ passwords.
Could be false. The stimulus tells us that users who forget their passwords use up the administrator’s time, but we don’t have any information about how much this costs. It is possible that a system administrator’s time is not expensive.
C
Passwords that are very easy to guess pose less of a security threat than passwords that are very difficult to remember.
Must be true. The stimulus tells us that very difficult passwords to remember are usually written down, a practice that poses the greatest security threat. If this practice poses the greatest threat, then the threat associated with passwords that are easy to guess is less.
D
Passwords that are random configurations of letters and numbers are the least likely to result in security breaches.
Could be false. The stimulus tells us that these passwords are the easiest for legitimate users to forget. If they are the hardest to remember, then they may usually be written down and therefore pose the greatest security threat.
E
The easier a password is to remember, the more secure the computer account.
Could be false. The stimulus does not describe a correlation between security risk and the ease of remembering a password. It is possible that there is a point where the security level maximizes even though the password could change to become easier to remember.
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that wood ants use conifer resin in their nests to protect against disease. This is because conifer resin kills bacteria that can harm wood ants.
Notable Assumptions
The author assumes a causal relationship from a correlation. In other words, the author assumes that just because the resin has disinfectant properties, these properties are the reason why wood ants use it in their nests, instead of some other reason—maybe the resin helps make a strong nest, or the ants just like the smell of it.
A
whether conifer resin retains its disinfectant properties over very long periods of time
Irrelevant—we have no reason to believe the resin’s disinfectant properties would need to last a long time for the ants to use it for disease-protection measures. Maybe the resin doesn’t retain its disinfectant properties for long, and the ants just replace it periodically.
B
whether the nests of European wood ants generally contain more conifer resin at some times of the year than at others
Irrelevant—we don’t know anything about how the time of year could affect why the ants use the resin. We’d have to make way too many assumptions for this to be useful.I
C
whether any ant species other than European wood ants use conifer resin in their nests
Irrelevant—the argument is solely about European wood ants. What other ants use in their nests is not relevant to the author’s conclusion.
D
whether the use of conifer resin affords structural benefits to European wood ants’ nests
This is useful—if the answer is yes, we have another use for the resin. This weakens the author’s conclusion that the ants use it for its disinfectant properties. If no, the author’s argument is strengthened, as a potential alternative explanation is eliminated.
E
whether the disinfectant properties of conifer resin evolved as a disease-protection measure for conifer trees
Irrelevant—how other organisms use conifer resin, or how it developed its disinfectant properties, are not relevant to the argument, which is about how and why the ants use the resin.
One of the hardest yet most helpful practices during Blind Review is to create your own analogous arguments. Consider the following analogy which should demonstrate the issue of smuggling facts of the world which you believe into other people's minds.
Oranges contain vitamin C which is an essential vitamin. (This is a fact. You just read it so even if you didn't already believe it before, you certainly believe it now.)
Many people criticize oranges because they believe that the fruit has no health benefits. These same people believe that vitamin C has health benefits.
Here's the entire content of those people's beliefs:
b1 - Oranges have no health benefits.
b2 - Vitamin C has health benefits.
Can we say that these people hold contradictory beliefs about oranges? No, we cannot. Look again at b1 and b2. There is no contradiction. You're tempted to say yes because you know that oranges contain vitamin C and you think to yourself surely they must believe this too. This is the trap that (A) lays out.
But, what we can say for sure is that these people's b1 is just wrong. They're just wrong about oranges' health benefits. Because b1 contradicts a fact of the world. This is (C), the correct answer.
Summary
Etiquette helps people get along with each other. Some people criticize etiquette because they believe it has no beneficial effects for society. However, these same people also believe that social harmony is good.
Strongly Supported Conclusions
Some people who criticize etiquette mistakenly believe that it has no beneficial effects for society.
A
Many people who criticize etiquette have contradictory views about etiquette.
This answer is unsupported. We don’t know whether the people who think that etiquette helps people get along are also the same people who think etiquette has no beneficial effects for society. These are two different viewpoints embedded within the stimulus.
B
Many people have respect for etiquette even though they criticize it.
This answer is unsupported. We don’t know whether the people who have respect for etiquette are the same people who criticize etiquette. These are two different viewpoints embedded within the stimulus.
C
Many people who criticize etiquette are mistaken about its beneficial effects for society.
This answer is strongly supported. Some people who criticize etiquette are mistaken about its beneficial effects because these same people think social harmony is beneficial.
D
If people were more considerate there would be no need for etiquette.
This answer is unsupported. We don’t know from the stimulus what would cause the need for etiquette to decrease.
E
Kindness and social harmony are highly beneficial to society.
This answer is unsupported. To say that these factors are “highly” beneficial is too strong. They may be beneficial to some degree, but that degree is undetermined by the stimulus.