Summarize Argument
The author concludes that increasing air traffic allowed at the airport beyond its original design capacity would decrease safety. This is based on studies done 30 years ago, which showed that safety was reduced at every airport where the permitted air traffic was increased beyond the airport’s original design capacity, even when those airports made use of the latest (as of 30 years ago) safety technology.
Identify and Describe Flaw
The author overlooks the possibility that the latest safety technology today is significantly more advanced than the latest safety technology as of 30 years ago. In other words, perhaps the results obtained in the studies from 30 years ago aren’t very relevant to what would happen as a result of increased air traffic today, due to better technology.
A
The argument draws a conclusion on the basis of a general statement that has in turn been inferred from a very limited number of particular instances.
The argument is based on numerous studies. We have no reason to think that these numerous studies are only a “very limited number of particular instances.”
B
The argument fails to consider the possibility that whether an airport can allow more air traffic than it was originally designed for without reducing safety depends largely on what the latest technology is.
(B) points out that the latest technology (as of today) might allow for more air traffic safely, even though older technology didn’t. What was the “latest” technology 30 years ago isn’t necessarily the latest technology today.
C
The argument fails to consider the possibility that the city council members who support the increase are aware of the studies that were conducted 30 years ago.
The argument’s reasoning has nothing to do with the city council members. The argument is based on the numerous studies conducted 30 years ago. Whether people who disagree with the author are aware of those studies doesn’t affect the reasoning.
D
The argument confuses an absence of evidence for the claim that the airport can safely permit air traffic in excess of its original design capacity with the existence of evidence against this claim.
The argument’s reasoning doesn’t point out that there’s a lack of evidence for the view that airports can safely increase air traffic. The reasoning is based on studies from 30 years ago.
E
The argument fails to consider that a slight increase in safety risks might be acceptable if it yields overriding benefits of another kind.
The author doesn’t conclude that we should increase air traffic. So whether risks are acceptable or not are irrelevant. The conclusion is simply that increasing air traffic beyond original capacity will decrease safety.
Renate: It’s true that the store is gone, but its closing had little to do with the product it sold. All this means is that the market for rugs in Glendale is now wide open.
Speaker 1 Summary
Mario concludes that we should avoid starting a new rug business in Glendale. This is because the only rug store in Glendale has gone out of business, which suggests there’s little demand for rugs there.
Speaker 2 Summary
Renate’s implicit conclusion is that if we’re interest in opening a new business in Glendale, we don’t need to avoid rugs. This is because the closing of the previous rug store didn’t have to do with demand, which indicates that the market for rugs in Glendale is now completely open.
Objective
We’re looking for a point of disagreement. The speakers disagree about whether rugs are a product to avoid when starting a new business in Glendale.
A
the rug store in Glendale sold rugs of inferior quality
Neither speaker expresses an opinion. Nobody discusses the quality of rugs sold by the previous store or whether the store’s closing suggests anything about the quality of rugs.
B
it is a good idea to open a rug store in Glendale
This is a point of disagreement. Mario thinks it’s not a good idea. Renate thinks it can be.
C
it is possible to determine the market for rugs in Glendale
If “market for rugs” means anything beyond the general size of the market, then the speakers don’t have an opinion. If it means only the general market size, then both think we can determine it. Mario thinks the market is small. Renate thinks the market is wide open.
D
any other stores have gone out of business in Glendale
Neither expresses an opinion. Nobody discusses other stores in Glendale or whether they have gone out of business.
E
rug stores can close because of insufficient demand for rugs
Renate doesn’t express an opinion. She acknowledges that the prior rug store closed, but says it wasn’t because of lack of demand. She doesn’t say anything suggesting lack of demand for rugs can or cannot lead to closing of a rug store.
Summarize Argument: Counter-Position
Certain researchers concluded that, on average, 50-year-olds are more altruistic than 20-year-olds. This conclusion was based on a study in which twice as many 50-year-olds as 20-year-olds, out of a sample of 100 of each group, reported sometimes donating blood.
The author concludes that there’s reason to be skeptical of the researchers’ conclusion. This is because many people hesitate to admit that their behavior doesn’t fit what society expects. (The implication is that there’s another explanation for the disparity in reported blood donations.)
The author concludes that there’s reason to be skeptical of the researchers’ conclusion. This is because many people hesitate to admit that their behavior doesn’t fit what society expects. (The implication is that there’s another explanation for the disparity in reported blood donations.)
Describe Method of Reasoning
The author presents an alternative hypothesis to explain the disparity in reported blood donations. Maybe the 50-year-olds exaggerated?
A
showing that the data are based on an unrepresentative sample
There’s no comment about the background/features of people who were part of the study. What the author’s suggesting is that we can’t trust the “reports.” This doesn’t mean the samples were unrepresentative.
B
offering an alternative explanation of some of the data
The author suggests that one reason the 50-year-olds might have reported donating blood at a higher rate than the 20-year-olds reported doing so is that many 50-year-olds might not have wanted to admit that they didn’t donate.
C
showing that one cannot directly observe altruism
The author could believe that it’s possible to directly observe altruism (for ex., we see someone give away a ton of money for free). The author doesn’t show that this is impossible to observe. What she suggeests is that some 50-year-olds might be lying about donating blood.
D
criticizing the motives of the researchers
The author doesn’t say anything about the motives of the researchers. She simply comments on an alternative explanation for the results of the study.
E
offering a specific counterexample
The author doesn’t bring up a 50-year-old who didn’t donate, or a 20-year-old who did. (These aren’t “counterexamples” anyway, since you can’t have a counterexample to an average or a general tendency, which already allow for exceptions.)
Wilkerson: But before the project began, over 5,000 homes in the community had no electricity. Surely bringing electricity to around 3,000 homes counts as a success for the project.
Speaker 1 Summary
Monroe claims that a recent project was a failure. Why? Because the project’s goal was to bring electricity to as many homes as possible in the community. But now that the project is over, 2,000 homes still don’t have electricity. To Monroe, this shows that the project didn’t meet its goal.
Speaker 2 Summary
Wilkerson’s unstated conclusion is that the project was successful. How do we know? Because the project did bring electricity to 3,000 homes. And Wilkerson believes that providing electricity to 3,000 homes counts as a success, so we can infer the conclusion that the project was successful.
Objective
We want to find a disagreement between Monroe and Wilkerson. They disagree about whether or not the project was a failure.
A
Approximately 2,000 homes in the community are still without electricity.
Both speakers agree that this is true. Monroe claims this explicitly, and Wilkerson gets to it indirectly by saying that of 5,000 homes without electricity, 3,000 are now connected, which leaves 2,000 without electricity.
B
Before the organization’s project began, over 5,000 homes in the community had no electricity.
Wilkerson agrees with this, and Monroe never states a position. Monroe doesn’t discuss how many homes lacked electricity before the project started, so there’s no reason to think that the speakers disagree.
C
The organization’s project must be considered a failure if any home in the community has no electricity.
Wilkerson disagrees, but Monroe never agrees with this. Monroe thinks that 2,000 homes having no electricity counts as a failure, but doesn’t give a lower bound to this failure condition. Maybe if only one home had no electricity, Monroe would be content—we don’t know.
D
The stated goal of the project was to reduce as much as possible the number of homes in the community that lack electricity.
Monroe states this directly, and Wilkerson never disagrees. Wilkerson has different criteria for success than Monroe, but still doesn’t contradict Monroe about the project’s stated goal.
E
Leaving approximately 2,000 homes in the community without electricity at the conclusion of the project counts as a failure for the project.
Monroe agrees with this, and Wilkerson disagrees, making this their disagreement. From 2,000 homes lacking electricity, Monroe concludes that the project failed, implying this principle. However, Wilkerson thinks the project succeeded despite those 2,000 homes.