Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that ants are more likely to live in healthy orchid species because the ants store organic matter, thereby providing the orchids with additional nutrients.
Notable Assumptions
The author assumes that the organic matter brought by the ants are *causing* the orchids to be healthier. It could be equally true that healthy orchids attract ants to store their nectar (or some other variable).
The author also assumes that the ants’ presence does not harm the orchid in other ways.
The author also assumes that the ants’ presence does not harm the orchid in other ways.
A
Microscopic organisms that are present in the orchids’ roots break down the organic matter stored there by the ants.
If anything, this strengthens the link between organisms, bolstering the health of orchids. Thus, this does not weaken the argument.
B
The nutrients present in the organic matter stored by the ants are the same as those present in the soil in which the orchids are found.
While this suggests that the ants may not provide *unique* nutrients, it does not explain why the orchids are healthier. You have to make some unwarranted assumptions for this to work.
C
The ants that live in hollow places in the roots of orchids prey on an insect species whose members eat the orchids’ roots.
While this may look unrelated, it provides another explanation for *why* orchids with ants are healthier. If the ants hunt a species prone to eating the orchid’s roots, it explains the orchid’s improved health.
D
The ants that live in hollow places in the roots of orchids do not play a role in pollinating the flowers of the plant.
It does not matter whether the ants pollinate the plant. This does not provide an alternative explanation or weaken the argument.
E
Most plant species whose roots, stems, or leaves harbor insects are more prone to disease and rot than are other plants.
This is not specific enough to be applied to the ants and orchids. Also, it does not address why the orchids are healthier.
Summarize Argument: Phenomenon-Hypothesis
The journalist hypothesizes that driving during the day is more dangerous than driving at night. She supports this by citing a study showing that the number of fatal traffic accidents was higher during the day than at night in each of the last ten years.
Notable Assumptions
The journalist assumes that the number of fatal accidents is the best indicator of driving danger and directly translates to it being more dangerous to drive during the day. She doesn’t consider other factors like traffic volume, non-fatal accidents, or other potential risks.
A
Only during the day are there more unsafe than safe vehicles on the road.
This strengthens the hypothesis by providing an additional reason why daytime driving is more dangerous and nighttime driving is safer. If there are only more unsafe vehicles during the day, then there are more safe drivers than unsafe drivers at night.
B
There is decreased law enforcement presence during the day.
This strengthens the hypothesis by providing an additional reason why daytime driving is more dangerous. Decreased law enforcement during the day may increase the likelihood of reckless drivers, speeding, and other risk factors.
C
Persons drive more cautiously during the night than during the day.
This strengthens the hypothesis by providing an additional reason why daytime driving is more dangerous and nighttime driving is safer. Because people drive more cautiously during the night than during the day, daytime driving is more dangerous.
D
The number of travelers per vehicle has increased over the past ten years.
Irrelevant— we don’t know whether this applies to vehicles traveling in the day, at night, or both. We also don’t know whether having more travelers per vehicle makes driving more or less dangerous. So, (D) doesn’t strengthen the argument.
E
Persons drive faster during the day than during the night.
This strengthens the hypothesis by providing an additional reason why daytime driving is more dangerous and nighttime driving is safer— because people drive faster during the day than at night.
Summarize Argument
The author believes that Winchester Township should close its smaller branch libraries to create one larger, and better stocked, library to better meet residents’ needs. This is because the town cannot afford to keep several of the smaller libraries well stocked, but could afford to do so if they had one larger library.
Notable Assumptions
The author assumes that the selection of books available outweighs all other factors for meeting their residents’ needs. Perhaps a single location will make the library unavailable for many residents.
A
Many Winchester residents never use the branch libraries because of the irregular hours each branch keeps.
If anything, this strengthens the argument because it suggests that the residents would not really mind if the branch offices close.
B
Most Winchester residents have complained about the selection of books at the branch libraries.
Just because most residents have not complained about the selection of books, that does not undermine the reasoning that a larger selection would better meet the residents’ needs.
C
The only possible site for a new library is not readily accessible to most Winchester residents.
This directly calls out the author’s key assumption: that moving the library to a single location won’t have severe consequences. If the new location is not accessible, then it may not better meet residents’ needs.
D
It would cost Winchester a significant amount of money to build a larger library.
This is pretty much implied in the stimulus. This argument is about the *effectiveness* of the plan, not the monetary cost
E
Each of Winchester’s branch libraries attempts to cater to the tastes of the residents of the entire township.
While this may explain why they have limited selections, it does not weaken the claim that having a single well-stocked library would better meet residents' needs.
Ayla: The best way to combat false views is to challenge them in public. Once Carl’s views are subjected to the kind of public scrutiny the forum provides, people will see them for what they are because the forum will provide convincing arguments against them.
Speaker 1 Summary
Bernard concludes we shouldn’t invite Carl to speak at the forum. This is because Carl’s views are false and dangerous. We don’t want to support adoption of those views, and inviting him to speak would help spread those views.
Speaker 2 Summary
Ayla’s implicit conclusion is that we should invite him to speak. This is because challenging his views in public is the best way to combat them.
Objective
We’re looking for a disagreement. The speakers disagree about whether we should invite Carl to the forum.
A
one should always avoid legitimizing a view whose adoption one wishes not to support
Ayla doesn’t have an opinion. Although she wants to challenge Carl’s false views, we don’t know what she thinks about views she wishes not to support. She might think it’s OK to legitimize views she doesn’t support, as long as they’re not false.
B
people will see the falsity of every dangerous idea for which they are furnished with forceful counterarguments
Bernard doesn’t have an opinion. He doesn’t discuss what happens when people encounter counterarguments against views.
C
the best way to fight erroneous ideas involves allowing the public expression of these ideas
The speakers disagree. Bernard implicitly thinks this is not the best way, because he says not to invite Carl. If he thought this was the best way to fight Carl’s ideas, he wouldn’t make this recommendation. Ayla thinks the best way to fight Carl’s ideas is to allow him to speak.
D
people who hold false views tend to pose a danger to society
Ayla doesn’t have an opinion. She doesn’t discuss the idea of danger or whether some views can be dangerous.
E
one should not encourage the adoption of dangerous views
Ayla doesn’t have an opinion. She doesn’t discuss the idea of danger or whether we should encourage adoption of dangerous views.
News report: Some recently invented television screens are built out of small tiles seamlessly joined together, each tile a separate miniature screen. Television sets with these compound screens are just a few inches thick. For a noncompound screen in a set of this thickness, the larger the screen is, the dimmer it is. However, each tile in a compound screen is small enough to be quite bright. Moreover, an unlimited number of the tiles can be joined together, without making the resulting screen any less bright or the set any thicker.
Summary
Compound television screens are built by joining together small tiles that are each a separate miniature screen.
TVs with compound screens are just a few inches thick.
When the thickness of TVs with noncompound screens is held constant, the larger a screen is, the dimmer it is.
Each tile in a compound screen is small enough to retain brightness.
In compound screens, you can have an unlimited number of tiles joined together without making the screen less bright or the TV set thicker.
Notable Valid Inferences
For TVs with compound screens, having a larger screen doesn’t mean that the screen will be dimmer. These TVs can be bright and large.
A
The technology used to make compound television screens is not appropriate for television sets with relatively small screens.
Could be false. There is no information in the stimulus to indicate that compound screens can’t be used for TVs with small screens.
B
There is a great consumer demand for television sets that are just a few inches thick and that have very large screens.
Could be false. The stimulus does not mention consumer demand, so we cannot make inferences about consumer demand.
C
In a television set with a noncompound screen, the thicker the television set, the brighter the screen.
Could be false. The stimulus only discusses noncompound screens “in a set of this thickness.” The stimulus does not discuss how changing the thickness of the TV impacts the brightness of the screen.
D
Television sets that are just a few inches thick can now be made with screens that are both bright and very large.
Must be true. TVs with compound screens are just a few inches thick, and they can have screens that are both bright and very large.
E
Television sets with compound screens do not have any disadvantages relative to sets with noncompound screens.
Could be false. This is outside of the scope of the stimulus; it could certainly be the case that there are many disadvantages of TVs with compound screens that the stimulus did not mention.