Legislator: My staff conducted a poll in which my constituents were asked whether they favor high taxes. More than 97 percent answered “no.” Clearly, then, my constituents would support the bill I recently introduced, which reduces the corporate income tax.

Summarize Argument
The author concludes that her constituents would support the bill she introduced. This is because the bill reduces the corporate income tax, and, according to a poll, her constituents do not “favor high taxes.”

Identify and Describe Flaw
The author assumes that the current corporate income tax constitutes a “high tax” in a way that the constituents would not favor. This overlooks the possibility that the corporate income tax is not actually high. It also overlooks that the constituents might have been referring to high personal taxes rather than corporate taxes.

A
fails to establish that the opinions of the legislator’s constituents are representative of the opinions of the country’s population as a whole
The author’s conclusion doesn’t extend to the population as a whole. So whether the constituents are representative of the whole population doesn’t matter.
B
fails to consider whether the legislator’s constituents consider the current corporate income tax a high tax
If the constituents don’t consider the current corporate income tax a high tax, that raises the possibility they wouldn’t necessarily support the bill simply because it reduces the corporate income tax. The constituents might be OK with the current corporate income tax.
C
confuses an absence of evidence that the legislator’s constituents oppose a bill with the existence of evidence that the legislator’s constituents support that bill
The author doesn’t argue, “Because there’s no evidence my constituents oppose the bill, they must support the bill.” The author’s premise concerns a poll about high taxes; it’s not a claim about a lack of evidence.
D
draws a conclusion that merely restates a claim presented in support of that conclusion
(D) describes circular reasoning. The conclusion does not restate anything in the premises, which describe the results of a poll.
E
treats a result that proves that the public supports a bill as a result that is merely consistent with public support for that bill
There is nothing that “proves” the public supports a bill. All we know from the premises concerning any kind of opinion is that the constituents are not in favor of high taxes. This doesn’t tell us whether they would support any bill.

14 comments

The number of automobile thefts has declined steadily during the past five years, and it is more likely now than it was five years ago that someone who steals a car will be convicted of the crime.

"Surprising" Phenomenon
Why is it more likely for a car thief to be convicted now than five years ago, even though car thefts have been steadily decreasing?

Objective
The correct answer will be a hypothesis that explains a key difference between car theft five years ago and car theft now. The difference will be one that causes car thieves to be more likely to be caught and convicted now than they were five years ago.

A
Although there are fewer car thieves now than there were five years ago, the proportion of thieves who tend to abandon cars before their owners notice that they have been stolen has also decreased.
This is a difference that explains why car thieves today are more likely to be caught than car thieves five years ago. Instead of abandoning stolen cars quickly, thieves now keep stolen cars for longer, making it easier to catch them.
B
Car alarms are more common than they were five years ago, but their propensity to be triggered in the absence of any criminal activity has resulted in people generally ignoring them when they are triggered.
This does not contribute to an explanation for why car thieves are more likely to be caught today. Even though there are more car alarms, people generally ignore triggered car alarms, so they are not causing car thieves to be caught.
C
An upsurge in home burglaries over the last five years has required police departments to divert limited resources to investigation of these cases.
If police are prioritizing the investigation of home burglaries over the last five years, there are fewer resources to investigate car theft. So we can’t conclude that car thieves are more likely to be caught today based on this explanation.
D
Because of the increasingly lucrative market for stolen automobile parts, many stolen cars are quickly disassembled and the parts are sold to various buyers across the country.
This does not contribute to an explanation for why car thieves are more likely to be caught today. If anything, the dispersal of stolen car parts might make it less likely for car thieves to be caught. We need a reason why it is more likely.
E
There are more adolescent car thieves now than there were five years ago, and the sentences given to young criminals tend to be far more lenient than those given to adult criminals.
The fact that there are more adolescent car thieves now doesn’t explain why car thieves are more likely to be convicted now. Also, whether a car thief receives a lenient sentence doesn’t provide information about the number of convictions or the reasons behind them.

22 comments

After the rush-hour speed limit on the British M25 motorway was lowered from 70 miles per hour (115 kilometers per hour) to 50 miles per hour (80 kilometers per hour), rush-hour travel times decreased by approximately 15 percent.

"Surprising" Phenomenon
Why did rush-hour travel times decrease after the rush-hour speed limit on the British M25 motorway was lowered?

Objective
The correct answer will be a hypothesis that explains a key difference between traveling on the British M25 motorway during rush-hour at a lower speed and traveling at a higher speed. That difference must result in shorter travel time when traveling at a lower speed.

A
After the decrease in the rush-hour speed limit, the average speed on the M25 was significantly lower during rush hours than at other times of the day.
We aren’t concerned with whether average speed is lower at rush-hour than at other times of day. We’re only concerned with rush-hour travel times and why those times decreased even though the speed limit also decreased.
B
Travel times during periods other than rush hours were essentially unchanged after the rush-hour speed limit was lowered.
Like (A), we are only concerned with rush-hour travel times and why those travel times increased after the rush-hour speed limit was lowered. Also, it shouldn’t be surprising that the change in rush-hour speed limit did not affect travel times during periods other than rush-hour.
C
Before the rush-hour speed limit was lowered, rush-hour accidents that caused lengthy delays were common, and most of these accidents were caused by high-speed driving.
This explains the key difference between driving on the M25 during rush-hour at a lower speed versus a higher speed. Driving faster led to more accidents, which caused longer travel times. When the speed limit was lowered, there were fewer accidents and shorter travel times.
D
Enforcement of speed limits on the M25 was quite rigorous both before and after the rush-hour speed limit was lowered.
The fact that the speed limit was rigorously enforced both before and after it was lowered only shows us that people probably drove at the correct speed, whether 50 mph or 70 mph. The question still remains: why did travel times decrease after the speed limit was lowered?
E
The number of people who drive on the M25 during rush hours did not increase after the rush-hour speed limit was lowered.
This could simply mean that the number of people on the M25 stayed the same before and after the rush-hour speed limit was lowered. Thus, it doesn’t help to explain why travel times decreased after the speed limit was lowered.

4 comments

A development company has proposed building an airport near the city of Dalton. If the majority of Dalton’s residents favor the proposal, the airport will be built. However, it is unlikely that a majority of Dalton’s residents would favor the proposal, for most of them believe that the airport would create noise problems. Thus, it is unlikely that the airport will be built.

Summarize Argument
The author concludes that it’s unlikely the airport will be built. This is based on the following:

If most of Dalton’s residents favor the proposal, the airport will be built.

It’s unlikely most of Dalton’s residents would favor the proposal. (This is a subsidiary conclusion based on the fact that most residents believe the airport would create noise problems.)

Identify and Describe Flaw
The author confuses a sufficient condition with a necessary condition. Although most of Dalton’s residents’ favoring the proposal is sufficient for the airport to be built, that doesn’t mean it’s necessary. It’s possible for the airport to be built even if most residents don’t favor the proposal.

A
treats a sufficient condition for the airport’s being built as a necessary condition
The author treats a sufficient condition for the airport’s being built (majority of Dalton’s residents favoring proposal) as a necessary condition. This overlooks that the airport can be built even if most Dalton residents don’t favor the proposal.
B
concludes that something must be true, because most people believe it to be true
Although the author does point out that most people believe the airport would create noise problems, the author does not conclude that the airport would create noise problems.
C
concludes, on the basis that a certain event is unlikely to occur, that the event will not occur
The author’s conclusion is that the airport is “unlikely” to be built. The conclusion does not assert that the airprot “will not” be built.
D
fails to consider whether people living near Dalton would favor building the airport
Whether people living near Dalton would favor building the airport doesn’t matter, because we care about the majority of Dalton residents. People living near Dalton are not residents of Dalton.
E
overlooks the possibility that a new airport could benefit the local economy
The author’s reasoning attempts to apply a conditional. Whether there could be benefits to the economy doesn’t relate to the author’s misinterpretation of the conditional. Also, the possibility of benefits doesn’t suggest Dalton’s residents would favor the proposal.

14 comments

Economist: If the belief were to become widespread that losing one’s job is not a sign of personal shortcomings but instead an effect of impersonal social forces (which is surely correct), there would be growth in the societal demand for more government control of the economy to protect individuals from these forces, just as the government now protects them from military invasion. Such extensive government control of the economy would lead to an economic disaster, however.

Summary

The stimulus gives us a causal chain. If the belief that getting fired is a product of social forces becomes widespread, that will increase demands for more extensive government control of the economy. If the government begins to control the economy more extensively, that will lead to economic disaster. We’re also told that the belief that getting fired is a product of social forces is accurate.

Strongly Supported Conclusions

Some accurate beliefs that become widespread might lead to negative consequences.

A
Increased knowledge of the causes of job loss could lead to economic disaster.

Strongly supported. We’re told that the belief social forces are responsible for job losses is correct. We also know that this belief, if widespread, can lead to economic disaster. So, if more people start to hold this correct belief, that might lead to economic disaster.

B
An individual’s belief in his or her own abilities is the only reliable protection against impersonal social forces.

Unsupported. We don’t know what can reliably protect against social forces. If anything, this is antisupported, because we know job losses aren’t caused by personal shortcomings. This suggests even if people didn’t have those shortcomings, that wouldn’t prevent job loss.

C
Governments should never interfere with economic forces.

Unsupported. Although extensive government control can lead to economic disaster, that doesn’t suggest other, less extensive, kinds of government involvement with the economy would be harmful.

D
Societal demand for government control of the economy is growing.

Unsupported. The stimulus says this will happen if the belief mentioned becomes widespread. But we don’t know if the belief is becoming more widespread.

E
In general, people should feel no more responsible for economic disasters than for military invasions.

Unsupported. Military invasions are mentioned as something that the government protects us against. But there’s no comparison made between military invasions and economic disasters concerning the responsibility people should feel.


9 comments

The giant Chicxulub crater in Mexico provides indisputable evidence that a huge asteroid, about six miles across, struck Earth around the time many of the last dinosaur species were becoming extinct. But this catastrophe was probably not responsible for most of these extinctions. Any major asteroid strike kills many organisms in or near the region of the impact, but there is little evidence that such a strike could have a worldwide effect. Indeed, some craters even larger than the Chicxulub crater were made during times in Earth’s history when there were no known extinctions.

Summarize Argument
The author concludes that an asteroid strike wasn’t responsible for most dinosaurs going extinct. This is because a major asteroid strike doesn’t have worldwide consequences, and even bigger asteroids than the one that supposedly caused the dinosaurs to go extinct have been accompanied by no known extinctions whatsoever.

Notable Assumptions
In order for the asteroid strike not to have caused most dinosaur extinctions, the author must believe that most dinosaurs weren’t located in the region that the asteroid struck. The author must also believe that climactic conditions at the time—i.e. drought—didn’t intensify the strike’s effects, perhaps by releasing significantly more dust than usual into the Earth’s atmosphere and blocking out the sun.

A
The vast majority of dinosaur species are known to have gone extinct well before the time of the asteroid impact that produced the Chicxulub crater.
The author likely agrees. The dinosaurs in question are just the “last dinosaur species.”
B
The size of a crater caused by an asteroid striking Earth generally depends on both the size of that asteroid and the force of its impact.
We don’t really care about the crater. We already know asteroids leaving larger craters caused no known extinctions.
C
Fossils have been discovered of a number of dinosaurs that clearly died as a result of the asteroid impact that produced the Chicxulub crater.
The author agrees that some dinosaurs died, but qualifies that the effects of the asteroid were regional. We need to weaken the claim that the asteroid couldn’t have caused widespread dinosaur extinctions.
D
There is no evidence that any other asteroid of equal size struck Earth at the same time as the asteroid that produced the Chicxulub crater.
The author never claimed there were two asteroids.
E
During the period immediately before the asteroid that produced the Chicxulub crater struck, most of the world’s dinosaurs lived in or near the region of the asteroid’s impending impact.
While the asteroid only had a regional effect, most dinosaurs lived in that region. Thus, the asteroid caused most dinosaur extinctions.

9 comments

Baxe Interiors, one of the largest interior design companies in existence, currently has a near monopoly in the corporate market. Several small design companies have won prestigious awards for their corporate work, while Baxe has won none. Nonetheless, the corporate managers who solicit design proposals will only contract with companies they believe are unlikely to go bankrupt, and they believe that only very large companies are unlikely to go bankrupt.

Summary
The very large interior design company Baxe dominates the corporate design market. Baxe has never won an award for corporate design, but some small companies have won awards for corporate design. However, corporate decision-makers only want to work with companies which they think are unlikely to go bankrupt, and they think that only very large companies are unlikely to go bankrupt.

Strongly Supported Conclusions
It is strongly supported that corporate managers only solicit designs from very large companies. Also, at least some corporations probably receive a lower quality of interior design from Baxe than they could from an award-winning smaller company. Also, the quality of interior design is not the primary factor in who controls the corporate design market. Finally, Baxe’s near monopoly does not depend on producing the best designs.

A
There are other very large design companies besides Baxe, but they produce designs that are inferior to Baxe’s.
This is not supported. The stimulus says Baxe is “one of the largest” design companies, which implies that there are other very large design companies, but we know nothing about the quality of their designs.
B
Baxe does not have a near monopoly in the market of any category of interior design other than corporate interiors.
This is not supported. Corporate interior design is the only category the stimulus discusses, so we just don’t know how Baxe’s market share compares in other categories.
C
For the most part, designs that are produced by small companies are superior to the designs produced by Baxe.
This is not supported. We can infer that at least some small companies probably produce at least some designs better than those produced by Baxe, but we don’t know how many. This means we have no idea if it’s “most” or only a few.
D
At least some of the corporate managers who solicit design proposals are unaware that there are designs that are much better than those produced by Baxe.
This is not supported. All we know about corporate managers is that they only work with very large companies. It’s entirely possible that they know of better designs out there, but just care more about a company’s stability.
E
The existence of interior designs that are superior to those produced by Baxe does not currently threaten its near monopoly in the corporate market.
This is strongly supported. Because smaller companies have won awards and Baxe hasn’t, we can infer that there are some designs better than those produced by Baxe. We also know that corporate managers don’t work with smaller companies, thus leaving Baxe’s near monopoly safe.

20 comments

Musicologist: Many critics complain of the disproportion between text and music in Handel’s da capo arias. These texts are generally quite short and often repeated well beyond what is needed for literal understanding. Yet such criticism is refuted by noting that repetition serves a vital function: it frees the audience to focus on the music itself, which can speak to audiences whatever their language.

Summarize Argument: Counter-Position

The musicologist argues that critics’ disapproval of the imbalance between the short, repetitive texts and the music in Handel's da capo arias can be refuted. This is because the critics overlook the important role of repetition. Repetition allows the audience to concentrate on the music, which can communicate universally, regardless of language.

Identify Conclusion

The conclusion is the musicologist’s claim that the critics’ criticism of the imbalance between the short, repetitive texts and the music in Handel’s da capo arias can be refuted: “such criticism is refuted”.

A
Handel’s da capo arias contain a disproportionate amount of music.

This is context. It provides background on a common criticism of Handel’s da capo arias.

B
Handel’s da capo arias are superior to most in their accessibility to diverse audiences.

The musicologist does not make this claim. While the nature of the repetition allows it to speak to audiences regardless of language, the musicologist does not compare this ability to other music.

C
At least one frequent criticism of Handel’s da capo arias is undeserved.

This is the main point of the musicologist’s reasoning, which is that while many critics complain of the imbalance between the text and music in Handel’s da capo arias, this criticism can be refuted. In other words, it is undeserved.

D
At least some of Handel’s da capo arias contain unnecessary repetitions.

The musicologist does not claim the repetitions are unnecessary. The musicologist instead claims the repetitions serve a vital function.

E
Most criticism of Handel’s da capo arias is unwarranted.

This is not the musicologist’s conclusion. The conclusion is that one specific criticism of Handel’s da capo arias can be refuted, not that most criticisms can be.


2 comments

Many scholars are puzzled about who created the seventeenth-century abridgment of Shakespeare’s Hamlet contained in the First Quarto. Two facts about the work shed light on this question. First, the person who undertook the abridgment clearly did not possess a copy of Hamlet. Second, the abridgment contains a very accurate rendering of the speeches of one of the characters, but a slipshod handling of all the other parts.

Summary

Some scholars are questioning who created the seventeenth-century abridgment of Hamlet. The person who undertook the abridgment did not possess a copy of Hamlet. The abridgment accurately renders the speeches of only one of the characters, and a poor rendering of all other parts.

Strongly Supported Conclusions

The abridgment was likely produced by an actor that played a single character’s role in Hamlet.

A
The abridgment was prepared by Shakespeare.

The facts we’re given about the abridgment do not support the idea that it was produced by Shakespeare.

B
The abridgment was created to make Hamlet easier to produce on stage.

We don’t know why the abridgment was created. The question the scholars are attempting to answer is who created the abridgment.

C
The abridgment was produced by an actor who had played a role in Hamlet.

If the facts about the abridgment are true, it fits that the abridgment was produced by an actor. An actor is likely to both not have a full copy of the play and only accurate memory of one of the character’s roles.

D
The abridgement was prepared by a spectator of a performance of Hamlet.

A spectator is unlikely to have produced an accurate rendering of one of the character’s speeches.

E
The abridgment was produced by an actor who was trying to improve the play.

Hamlet would not be improved by having an accurate rendering of one of the character’s roles and a poor rendering of all of the other character’s roles.


32 comments