Summarize Argument
The astronomer claims that Mount Shalko is a perfect site for a new proposed observatory. The support follows two lines of reasoning.
First, the site is suitable. There’s enough space for the building and no smog or light pollution from nearby cities.
Second, it would protect ecology, not harm it as some critics fear. The mountain currently has many recreational users who threaten its ecology, but recreational use would be precluded by the observatory.
First, the site is suitable. There’s enough space for the building and no smog or light pollution from nearby cities.
Second, it would protect ecology, not harm it as some critics fear. The mountain currently has many recreational users who threaten its ecology, but recreational use would be precluded by the observatory.
Notable Assumptions
The astronomer assumes that the site would remain suitable, for example that no new cities are planned to be built nearby in the near future.
The astronomer also assumes that the process of building the observatory, and the building’s ongoing presence on the mountain, wouldn’t harm the mountain’s ecology more than the current recreational use does.
The astronomer also assumes that the process of building the observatory, and the building’s ongoing presence on the mountain, wouldn’t harm the mountain’s ecology more than the current recreational use does.
A
More than a dozen insect and plant species endemic to Mount Shalko are found nowhere else on earth.
This does not weaken the argument, because the astronomer never contests the point that Mount Shalko is a unique ecological site. Instead, the argument is that the observatory would actually protect the mountain’s ecology by precluding recreational use.
B
A coalition of 14 different groups, as diverse as taxpayer organizations and hunting associations, opposes the building of the new observatory.
This does not weaken the argument, because the number or type of people who oppose building the observatory has no bearing on the astronomer’s argument. Just because there’s broad opposition, that tells us nothing about the merits of the astronomer’s claims.
C
Having a complex that covers most of the summit, as well as having the necessary security fences and access road on the mountain, could involve just as much ecological disruption as does the current level of recreational use.
This weakens the argument by undermining the astronomer’s claim that the observatory would protect the mountain’s ecology by eliminating recreational use. If the observatory could be just as harmful, then there’s no ecological benefit to building it.
D
The building of the observatory would not cause the small towns near Mount Shalko eventually to develop into a large city, complete with smog, bright lights, and an influx of recreation seekers.
This does not weaken the argument, because it partially affirms the astronomer’s assumption that no new cities will soon develop near Mount Shalko. In fact, by doing so, this strengthens the argument.
E
A survey conducted by a team of park rangers concluded that two other mountains in the same general area have more potential for recreational use than Mount Shalko.
This does not weaken the argument because whether or not other nearby mountains are suitable for recreational use is irrelevant. Mount Shalko is already used for recreation, and the observatory would stop that use. This doesn’t change any of that.
Summarize Argument
The author concludes that if volcanic ash caused dimmed sunlight and cool summers in China in 43 B.C., then the ash caused by Mount Etna must’ve spread over vast distances. This is because Mount Etna erupted in 44 B.C., and powerful volcanoes can cause such phenomena.
Notable Assumptions
The author assumes that if a volcano caused the phenomena in China, then that volcano was Mount Etna. This means the author assumes there were no other volcanos powerful enough to cause such phenomena in 44-43 B.C.
A
modern monitoring equipment can detect the precise path of volcanic ash in the atmosphere
This eruption was in 44 B.C. We don’t care if modern monitoring equipment can track volcanoes today.
B
the abnormal weather in China lasted for a full year or longer
We know powerful volcanoes can cause effects that last a year or longer. But that doesn’t mean those effects have to last a year or longer in order to associate them with a powerful volcanic eruption.
C
temperatures in Sicily were abnormally cold after Mount Etna erupted
Knowing the answer to this wouldn’t strengthen or weaken the author’s argument, which is that Mount Etna caused the phenomena in China. We don’t care about conditions in Sicily.
D
there were any volcanic eruptions near China around the time of Mount Etna’s eruption
If the answer is yes, then we have viable alternate explanation to the author’s: other volcanoes, rather than Mount Etna, caused cool summers and dimmed sunlight. If the answer is no, then it would seem Mount Etna was the volcano most likely to have caused such phenomena.
E
subsequent eruptions of Mount Etna were as powerful as the one in 44 B.C.
We’re not interested in subsequent eruptions. Knowing the answer wouldn’t tell us whether the 44 B.C. eruption likely caused the phenomena in China.
Summarize Argument
The columnist claims that we should ban the publication of polls during the week before an election. Why? A few reasons. Polls can influence how people vote. They’re also less reliable than people think, so can be misleading. In the week before an election, there’s also not enough time to dispute polls and correct their mistakes. Finally, only banning polls for one week minimally impairs freedom of expression.
Notable Assumptions
The columnist assumes that banning polls in the week before an election would reduce their influence over voters—in other words, that people are still influenced by such last-minute polls.
The columnist also assumes that voters have access to less-distorted sources of information that could better inform their votes in the absence of polls. Otherwise, limiting polls could hurt more than help.
The columnist also assumes that voters have access to less-distorted sources of information that could better inform their votes in the absence of polls. Otherwise, limiting polls could hurt more than help.
A
Few people are influenced by the results of polls published during the two weeks immediately prior to an election.
This weakens the argument, because it undermines the columnist’s assumption that banning polls in the week before an election would reduce their impact on voters. If everyone has already decided how to vote based on earlier polls, then the last week doesn’t make a difference.
B
The publication of poll results would not decide the winner of an uneven election race.
This does not weaken the argument, because we can’t assume that all election races will be uneven and so not decided by polls. If it’s still possible for even elections to be unduly influenced by poll results, the author’s argument is unharmed.
C
The publication of poll results may remove some voters’ motivation to vote because of the certainty that a particular candidate will win.
This does not weaken the argument. In fact, this just backs up the columnist’s point that polls can influence election results by providing a specific example of how this takes place.
D
The publication of poll results in the last weeks before an election draws attention to candidates’ late gains in popularity.
This does not weaken the argument—it actually underscores the importance of last-minute polls, and thus affirms the columnist’s assumption that those polls make a difference.
E
Countries in which such a ban is in effect do not generally have better informed citizens than do countries in which such a ban is not in effect.
This does not weaken the argument, because the columnist isn’t claiming that a ban would result in overall better informed citizens. This also doesn’t say that voters living under such a ban are any worse informed—and even if it did, we wouldn’t know if the ban was the cause.
Summary
Ants will vigorously attack invading insects that threaten a colony’s territory or food sources. These defensive tactics can successfully deter even flying insects, like wasps. However, ants do not attack all insects within their territory. For example, riodinid caterpillars commonly live among South American ants. These caterpillars are a favorite pray of wasps, but they also produce secretions the ants feed on.
Strongly Supported Conclusions
Riodinid caterpillars do not threaten South American ant’s territory or food sources.
Riodinid caterpillars are less likely to be preyed on by wasps when the caterpillars live among ants compared to those caterpillars that don’t live among ants.
Riodinid caterpillars are less likely to be preyed on by wasps when the caterpillars live among ants compared to those caterpillars that don’t live among ants.
A
The secretions produced by riodinid caterpillars are chemically identical to substances secreted by plants on which South American ants also feed.
We don’t know anything about the chemical makeup of the caterpillar’s secretions. We only know that the ants consume the secretions as food.
B
South American ants are more likely to be successful in defending their food sources and territory against intruders than are ants that live elsewhere.
We don’t know anything about ants that live elsewhere other than South America. The South American ants are only used as one example.
C
With the sole exception of riodinid caterpillars, South American ants will vigorously attack any organism that enters an area they inhabit.
We don’t know whether the riodinid caterpillar is the only exception. There could be other kinds of inspects the ants do not attack.
D
Among insect species that inhabit South America, wasps are the only kinds of organism other than ants that use riodinid caterpillars as a source of food.
We don’t know if wasps and South American ants are the only insects that use riodinid caterpillars as a food source.
E
Riodinid caterpillars in South America that live among ants are less likely to be attacked successfully by wasps than those that do not live among ants.
Since the ants’ attacks can effectively deter wasps, riodinid caterpillars living among ant colonies are probably less likely to be successfully preyed upon by wasps.
Primatologist: Although I agree that your assumption helped you make those predictions, your conclusion does not follow. You might as well argue that since we can predict the output of some bank cash machines by assuming that these machines actually want to satisfy the customers’ requests, these cash machines must really have desires.
Summarize Argument: Counter-Position
In response to the anthropologist’s claim that the assumption used to reach their prediction was true, the primatologist concludes that the anthropologist’s conclusion actually does not follow. As evidence, the primatologist compares the anthropologist’s argument to an argument about bank cash machines: the cash machines must really have desires because we can predict the output of the machines by assuming the machines want to satisfy customer requests.
Describe Method of Reasoning
The primatologist counters the position held by the anthropologist. She does this by presenting an analogous argument in order to show that the anthropologist’s reasoning is absurd.
A
citing various facts that could not obtain if the anthropologist’s conclusion were correct
The primatologist does not suggest that certain facts could not be true if the anthropologist’s conclusion was correct. She demonstrates that an additional argument is absurd in the same way the anthropologist’s argument is absurd.
B
offering another argument that has as its premise the denial of the thesis that the anthropologist defends
The primatologist’s argument relates to a completely different topic than the anthropologist’s argument. Her argument about bank cash machines does not have a premise about vervet monkeys.
C
applying one of the anthropologist’s reasoning steps in another argument in an attempt to show that it leads to an absurd conclusion
The reasoning step the primatologist applies is the reasoning step of concluding that because a prediction was correct, the assumption used to make that prediction is also correct.
D
attacking the anthropologist’s expertise by suggesting the anthropologist is ignorant of the analogy that can be drawn between animals and machines
The primatologist does not attack the anthropologist’s expertise. She addresses the anthropologist’s argument directly without focusing on the anthropologist’s personal characteristics.
E
suggesting that the anthropologist’s argument relies on a misinterpretation of a key scientific term
There is no key term or key phrase that the primatologist suggests the anthropologist is misinterpreting.
Merchant: But the amount spent by teenagers who congregate near mall stores constitutes a significant percentage of the total amount spent in those stores.
Summarize Argument: Counter-Position
In response to the manager’s claim that merchants should discourage teenagers from congregating near stores, the merchant points out that these teenagers contribute to a significant percentage of the total amount spent in these stores.
Describe Method of Reasoning
The merchant counters the position held by the manager. He does this by providing an additional consideration the manager’s argument fails to account for. If the mall’s goal is to prevent significant loss in overall sales, it may not be wise to prevent teenagers from congregating if those teenagers also contribute significantly to overall sales.
A
disputing the truth of claims the manager offers as support for the recommendation
The merchant does not claim that any of the manager’s premises are false. He only provides an additional premise for consideration.
B
giving information that pertains to the relation between the manager’s recommendation and the mall’s goal
The information that pertains to this relationship is the fact that teenagers congregating near stores contribute significantly to overall sales in those stores.
C
suggesting that the mall’s goal is an undesirable one
The merchant does not present a value judgment that the mall’s goal is undesirable. He only presents information that is additionally relevant to this goal.
D
contending that the manager’s recommendation is sound but for reasons other than those given by the manager
The merchant does not claim that the manager’s recommendation is sound. In fact, the merchant implies that the manager’s recommendation is likely not supported.
E
using the information cited by the manager to make an additional recommendation that would help achieve the mall’s goal
The merchant does not make a recommendation of his own. He only provides an additional consideration that is relevant to evaluating the manager’s recommendation.