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.
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.
In the video, I showed one way in which a small increase in average could have resulted in a large increase in the proportion of obese children. There are other ways too.
Here's one of those ways. Even if everyone gained exactly one pound, it may be the case that there were so many previously-almost-obese-children (within 1lb of obesity) or so few previously-obese children that the one pound gain increases the obese proportion dramatically.
Here's another. A lot of kids could have lost weight. To compensate for those kids losing weight, we'd have to have a lot of kids gaining weight to increase the total average by 1lb. Those kids that gain weight could be the large increase in obese children. If you're statistically inclined, think of it this way. Assume weight is normally distributed. Flatten the curve in the middle and shift the entire curve 1lb to the right. You would get substantially more obese children with a substantial flattening of the curve.
Young: Not necessarily. No one has the time to both be a competitive swimmer and hold an outside job. But unlike in the past, today’s competitive swimmers can make a living at their sport.
Summarize Argument: Counter-Position
Warner hypothesizes that better training regimens are the explanation for why more and more competitive swimmers are continuing to compete long beyond their university years.
Young proposes a different hypothesis for the increased longetivity of competitive swimming careers. Before, swimmers couldn’t make a living at their sport, so had to quit to get a job. But now, swimmers can make a living at their sport.
Young proposes a different hypothesis for the increased longetivity of competitive swimming careers. Before, swimmers couldn’t make a living at their sport, so had to quit to get a job. But now, swimmers can make a living at their sport.
Describe Method of Reasoning
Young proposes an alternative explanation for the longetivity of competitive swimming careers.
A
attempting to demonstrate that the evidence Warner advances actually undermines Warner’s conclusion
Warner’s evidence doesn’t undermine his own conclusion. Young simply presents a different explanation that Warner doesn’t consider.
B
presenting a counterexample in order to weaken the evidence offered in support of Warner’s conclusion
Warner doesn’t actually offer any evidence in favor of his hypothesis. In addition, Young doesn’t present an example of competitive swimmers who don’t have better training regimens or whose better training regimens don’t allow them to stay fitter for a longer time.
C
arguing that a condition that Warner takes to be sufficient to account for a phenomenon is necessary but not sufficient
Young doesn’t claim that anything is necessary in order to explain the increased longevitiy of competitive swimmers. He simply presents a different hypothesis.
D
maintaining that the evidence presented in support of Warner’s conclusion presupposes the truth of that conclusion
Young doesn’t accuse warner of using circular reasoning (where the conclusion assumes the truth of the premise).
E
offering an alternative to Warner’s explanation of a certain phenomenon
Young offers an alternative explanation for the increased longevity of competitive swimmers. Rather than being a result of better training, it might be due to more swimmers being able to make a living as a swimmer nowadays.
Summary
The author concludes that the new law concerning cigarette packaging will not affect the smoking habits of most people who smoke cigarettes regularly. Why? Because most of these people rarely look at the packaging when they take out a cigarette.
Missing Connection
We’re trying to conclude that the new law won’t affect most regular smokers’ smoking habits. But the premise doesn’t tell us what allows us to know when a law will have no effect on regular smokers’ habits. All that the premise establishes is that most regular smokers rarely look at cigarette packaging when taking out a cigarette. But does failing to look at cigarette packaging when taking out a cigarette imply that the packaging can’t be effective in deterring people from smoking? Not necessarily.
To make the argument valid, then, we want to establish that if regular smokers rarely look at cig. packaging when taking out a cig., then the packaging won’t affect their smoking habits.
To make the argument valid, then, we want to establish that if regular smokers rarely look at cig. packaging when taking out a cig., then the packaging won’t affect their smoking habits.
A
If implementing certain regulations on the packaging of cigarettes would affect the smoking habits of those who smoke cigarettes regularly, those regulations should be implemented.
We’re trying to prove that the regulations on packaging won’t affect regular smokers’ habits. Whether the regulations should be implemented is a separate, irrelevant issue.
B
If those who regularly smoke cigarettes look at disturbing pictures of smoking-related diseases frequently, it is likely to affect their smoking habits.
(B) is designed to reach a conclusion that something is likely to affect smoking habits; but we want to prove that something will NOT affect smoking habits.
C
Almost all people who regularly smoke cigarettes are already familiar with the risks that smoking poses to their health.
Even if most regular smokers are already familiar with the risks of smoking, that doesn’t guarantee that packaging warnings won’t affect their smoking habits. Perhaps the packaging could encourage them to smoke less often. So (C) doesn’t guarantee that the new packaging won’t affect smoking habits.
D
The new packaging cannot affect the smoking habits of people who regularly smoke cigarettes unless they frequently look at the packaging when taking out cigarettes.
(D) establishes that in order for the new packaging to affect smoking habits of someone, that person must frequently look at the packaging when taking out cigs. We know that most regular smokers don’t frequently look at the packaging when taking out cigs. According to (D), then, the new packaging cannot affect the smoking habits of those people.
E
Most people who regularly smoke cigarettes would be unable to describe the logo of their usual brand of cigarettes if asked to do so.
(E) doesn’t establish anything about what’s required for packaging to affect smoking habits. Remember, we already know that most regular smokers don’t frequently look at cig. packaging when taking out cigs. What we want is to connect that fact to lack of effectiveness in changing smoking habits.
Janet: Although it’s true that nurse anesthetists receive excellent training, only doctors have the broader medical training to handle the rare emergencies that can arise.
Speaker 1 Summary
Nurses trained in administering anesthetics should be allowed to anesthetize patients without doctor supervision. Why? Because anesthesia has gotten remarkably safe in recent decades.
Speaker 2 Summary
Even though nurse anesthetists receive excellent training, only doctors have the broader training to handle rare emergencies that can arise.
Objective
We need a statement that Edgar and Janet disagree on. They disagree whether nurse anesthetists should have doctor supervision. Edgar disagrees because anesthesia has gotten safer. Janet agrees because only doctors have the necessary training to handle rare emergencies.
A
nurses should ever be allowed to anesthetize patients
Both speakers agree with this statement. Edgar thinks that nurses should be able to anesthetize patients without doctor supervision. Janet thinks that nurses should be able to anesthetize patients with doctor supervision.
B
emergencies that can develop from anesthesia are rare
Edgar does not express an opinion on this statement. Edgar thinks that anesthesia has gotten safer, but this is not necessarily equivalent to expressing that emergencies are rare.
C
nurses should be given more training in administering anesthetics
Neither speaker expresses an opinion on this statement. In fact, the speakers may disagree, since both acknowledge that nurse anesthetists are specially trained.
D
the safety of anesthesia has improved in recent decades
Janet does not express an opinion on this statement. Janet only expresses that only doctors are capable of handling rare emergencies.
E
the administration of anesthetics by a nurse should always be supervised by a doctor
Edgar and Janet disagree on this statement. Edgar disagrees and thinks nurse anesthetists should be able to anesthetize patients without doctor supervision. Janet agrees because only doctors are capable of handling a rare emergency.
Summarize Argument: Counter-Position
The author concludes that England’s mild winters are not due to the Gulf Stream, which brings warm water to England. The author bases this conclusion on the fact that parts of the west coast of North America have mild winters, even though those parts don’t get currents that bring warm water to them.
Identify Conclusion
The conclusion is the author’s rejection of the wide belief regarding the cause of England’s mild winters: “[T]his belief is mistaken.”
A
It is widely believed that England’s mild winters must be due to the Gulf Stream.
This is other people’s position. The author rejects this.
B
The belief that England’s mild winters must be due to the Gulf Stream is mistaken.
This restates the author’s conclusion.
C
It is true that the Gulf Stream brings tropical water to England.
This is a concession. Despite this point, however, the author concludes that the Gulf Stream does not cause England’s mild winters.
D
In the Pacific Ocean, the Kuroshio Current brings tropical water only as far north as Oregon.
This is part of the author’s support for the conclusion.
E
North America’s west coast has mild winters well north of Oregon.
This is part of the author’s support for the conclusion.
Summary
Severing a motor nerve kills part of the nerve. However, the nerve can regenerate. When regenerating, a nerve grows about 1 millimeter every day from the point of severing toward the muscle the nerve controlled. For example, a severed motor nerve controlling a hand would take longer to regenerate if the nerve was severed at the shoulder compared to the wrist. Growing nerve cells require the original nerve sheath to guide them to the muscle that lost function. However, the original nerve sheath disintegrates after three months unless living nerve tissue exists within it.
Strongly Supported Conclusions
If an original nerve sheath has living nerve tissue, then the likelihood a motor nerve can regenerate increases.
A
Doubling the speed at which new nerve cells grow will double the likelihood that a severed motor nerve will reach the muscle it had controlled.
This answer is unsupported. We don’t know if the speed at which nerve cells grow is directly proportional with the likelihood it will reach a muscle.
B
It is sometimes possible, once a nerve sheath has begun to disintegrate, to reverse or slow the process of disintegration.
This answer is unsupported. We don’t know whether it’s possible to reverse or slow the process of disintegration.
C
If a severed motor nerve does not regenerate successfully within three months after being severed, functioning cannot be restored to the muscle that the nerve had controlled.
This answer is unsupported. We don’t know if successful nerve regeneration within three months is necessary for a muscle’s function to be restored.
D
If living nerve tissue could be implanted and sustained within the original sheath of a severed motor nerve, the likelihood that the nerve will regenerate would increase in some cases.
This answer is strongly supported. The only exception to disintegration is if living nerve tissue still exists in the sheath. If living nerve tissue could be injected, then the likelihood of regeneration increases even if only slightly.
E
Without surgical intervention, a muscle that has lost function because of a severed motor nerve is unlikely to regain that function.
This answer is unsupported. We don’t know if surgical intervention is required to restore function to a muscle severed from a motor nerve.