Ms. Yerky: The blood contains no such substance. Laboratory experiments involving a number of animals, including the arctic squirrel, have shown that a vial of blood from any of the animals freezes at just the same temperature as does a vial of water.
Summarize Argument: Counter-Position
Xu concludes that the arctic squirrel’s blood has a substance that prevents it from freezing at the freezing temperature of water. This is based on the claim that the squirrel’s blood temperature falls below the freezing temperature of water when the squirrel is hibernating, but the blood never freezes during hibernation.
Yerky concludes that the squirrel’s blood doesn’t have a substance that keeps it from freezing at water temperature. This is based on the claim that lab experiments show the squirrel’s blood freezes at the same temperature that water freezes.
Yerky concludes that the squirrel’s blood doesn’t have a substance that keeps it from freezing at water temperature. This is based on the claim that lab experiments show the squirrel’s blood freezes at the same temperature that water freezes.
Describe Method of Reasoning
Yerky presents evidence that suggests Xu’s conclusion is wrong.
A
presenting evidence that supports a conclusion inconsistent with Mr. Xu’s conclusion
Yerky presents evidence (the lab experiment results) that supports a conclusion that contradicts Xu’s conclusion. Yerky concludes squirrel blood doesn’t have a substance that keeps it from freezing at water temperature. This contradicts Xu’s conclusion.
B
showing that the evidence offered by Mr. Xu was collected by means of unreliable methods
Yerky doesn’t comment on the way in which Yerky’s evidence was gathered. We don’t know why Xu thinks that a squirrel’s blood doesn’t freeze during hibernation, or that a squirrel’s blood gets colder than the freezing temperature of water during hibernation.
C
offering an alternative explanation for why the squirrel’s blood fails to freeze at the temperature at which water freezes
Yerky probably doesn’t agree that a squirrel’s blood fails to freeze at the freezing temperature of water. The lab tests show that it does freeze at that temperature. So there’s no way that Yerky provides an explanation for a phenomenon that she doesn’t even think happens.
D
showing that a key term used by Mr. Xu is ambiguous
None of the terms in Xu’s argument is used ambiguously. “Hibernation” means the same thing throughout Xu’s argument. Same with “blood” and “freezing” and “temperature” and every other word.
E
showing that the evidence provided by Mr. Xu has no bearing on the point at issue
Yerky brings up lab results that suggest Yerk’s conclusion is wrong. But this doesn’t mean Xu’s evidence has no bearing (i.e. is irrelevant.) Evidence can be relevant, even if its ultimately not persuasive.
Summarize Argument
A group of psychologists argues that young children’s compassionate behavior in certain situations demonstrates that moral behavior begins early in life. A second group of psychologists disagrees, claiming that an empathetic response (by itself) is not a moral behavior. They argue that moral behavior requires an understanding of moral principles and reasoning skills, which the children lack based on their unsophisticated verbal responses to hypothetical dilemmas.
Notable Assumptions
The children’s verbal responses to the hypothetical dilemmas accurately measures their moral reasoning skills.
A
The children studied by the second group of psychologists displayed a slightly higher level of moral reasoning when they were well rested than when they were tired.
That some children displayed “slightly higher” levels of reasoning when they were well-rested does not impact the argument. The argument is focused on whether the children’s responses to hypothetical dilemmas indicate their moral reasoning abilities.
B
Adults who respond to hypothetical moral dilemmas display a much higher level of moral reasoning than do children who responded to the same hypothetical moral dilemmas.
If anything, this supports the argument by showing that moral reasoning develops later in life. It does not cast doubt on the claim that *children* lack moral reasoning skills.
C
The children studied by the second group of psychologists displayed a slightly higher level of moral reasoning in response to hypothetical dilemmas involving adults than in response to hypothetical dilemmas involving children.
This only details some variation in how the children responded to certain hypotheticals. It does nothing to cast doubt on the second group of psychologists’ main conclusion.
D
In actual situations involving moral dilemmas, children display a much higher level of moral reasoning than did the children who, in the study by the second group of psychologists, responded only to hypothetical dilemmas.
This calls out a key assumption and gets to the heart of the argument’s reasoning. This suggests that the children’s verbal responses to hypothetical dilemmas do not accurately reflect their reasoning in real-life situations.
E
Some adults who respond to hypothetical moral dilemmas reason at about the same level as children who respond to the same hypothetical moral dilemmas.
A comparison between children and adults does nothing to weaken the argument. The argument hinges on children’s subpar response to hypothetical dilemmas and that “proving” that they do not have moral reasoning.
Summarize Argument: Counter-Position
The business writer concludes that it would be a mistake for the manufacturer of Corrine wristwatches to increase the supply to meet demand for the following reasons:
1. The current high demand is due to the public’s perception that the watches are in short supply.
2. This is because they are produced in very small quantities.
3. The scarcity of these watches drives desire.
4. If the supply were increased, the perceived scarcity of the watches would diminish
5. This would decrease the demand for the watches.
1. The current high demand is due to the public’s perception that the watches are in short supply.
2. This is because they are produced in very small quantities.
3. The scarcity of these watches drives desire.
4. If the supply were increased, the perceived scarcity of the watches would diminish
5. This would decrease the demand for the watches.
Identify Argument Part
This is the conclusion of the argument. The following sentences explain the reasoning to support this claim.
A
an introductory claim that describes the position to be refuted by the argument
The claim is not refuted by the argument. It is the main conclusion that is supported by everything else that follows.
B
a justification of the relevance of the evidence cited
The claim is not used to justify the relevance of the evidence. The evidence (premises) a are used to support this claim.
C
a premise of the argument
The claim is not a premise. It is not used to support anything. It only receives support.
D
an opinion offered in support of one of the argument’s premises
The claim does not support a premise; it does not support anything, as it is the main conclusion of the argument.
E
the conclusion toward which the argument is directed
This is an accurate description of the claim. The entire argument supports the conclusion by explaining why increasing the supply of watches would be a mistake.
Summarize Argument
Dinosaurs were likely warm-blooded because the oxygen isotopes in their bones suggest that their limbs had the same body temperature as the rest of their body. And typically, the body temperature of modern cold-blooded animals much is higher than their limbs.
Notable Assumptions
The author assumes that the discrepancy in the body/limb temperature of modern cold-blooded animals was the same as cold-blooded animals during the time of the dinosaurs. The author also assumes that the process of determining body temperature from bones is applicable to dinosaur fossils.
A
Large warm-blooded animals keep their core body temperature slightly higher than the body temperature in their limbs.
This does not weaken because dinosaurs' core body and limb temperature are still much closer to the ratio of warm-blooded animals. Thus, this does not weaken the claim that dinosaurs were warm-blooded.
B
The fossilization process introduces changes to bones such that their original oxygen isotope ratios cannot be predicted.
This weakens the argument because it casts doubt on the process by which the evidence was discovered. If the fossilization process changes the oxygen distribution, then the evidence about the body temperature cannot be relied on to reach a sound conclusion.
C
Oxygen was more abundant in Earth’s atmosphere during the period in which the dinosaurs lived.
You must make several unwarranted assumptions to make this work. The fact that more oxygen was prevalent in the atmosphere does not mean dinosaur bones have more oxygen. AC B does a much better job of weakening the process of how the evidence was collected.
D
Small warm-blooded animals like mice tend to have more uniform body temperatures than do large warm-blooded animals like elephants.
This does not weaken the argument that dinosaurs are warm-blooded. This AC just compares small and large warm-blooded animals. You have to make many unwarranted assumptions for this to work.
E
Warm-blooded animals are more active and use more oxygen than cold-blooded animals.
This is irrelevant to the argument’s reasoning. This just provides a characteristic of warm-blooded animals but does not challenge the evidence or reasoning in the stimulus.
Actors generally learn their lines by focusing on the meanings of the words, the motivations of the characters uttering them, and the physical and emotional dimensions of their own performances. It seems likely that memory can be enhanced by factors such as emotion, action, and context, so this approach is probably more effective than mere rote memorization.
Summarize Argument: Phenomenon-Hypothesis
The author concludes that actors learn lines more effectively by focusing on the meanings, motivations, and physical and emotional aspects of performance, rather than simply using rote memorization. She supports this by hypothesizing that factors like emotion, action, and context can likely improve memory.
Notable Assumptions
The author assumes that, because factors like emotion, action, and context can likely improve memory generally, they also likely improve memory in the context of learning lines. She also assumes that the actors’ approach is more effective than rote memorization without considering any potential benefits of rote memorization.
A
Test subjects are best able to remember items on a shopping list when they are also told how those items will be used.
This strengthens the argument by providing data to support the hypothesis that context improves memory. This then strengthens the conclusion that contextualization is an effective approach to learning lines.
B
The actors who are able to deliver the greatest amount of dialogue most effortlessly are those who have spent the most time learning their lines.
This does not strengthen the argument because it doesn’t address the memorization method used. We don’t know if the actors in (B) used the author’s described approach, rote memorization, or another method.
C
Actors are more readily able to remember lines learned while making an appropriate motion—for example, walking across a stage—than lines learned without an accompanying action.
This strengthens the argument because it provides an example that supports the hypothesis that emotion, action, and context can improve memory. If actors memorize better by linking lines to actions, the author’s conclusion that this is an effective approach is much stronger.
D
People who try to memorize information by imagining that they are conveying it to somebody else who needs the information show higher retention than those who try to memorize the material by rote.
This strengthens the argument by providing an example in which memorization that involves emotion, motivation, and contextualization is more effective than rote memorization.
E
People with no acting experience are able to memorize and deliver lines from a play more accurately after they have read and understood the entire play.
This strengthens the argument by showing that line-learning is enhanced by understanding the context of a play. This supports the hypothesis that context improves memory and thus also supports the conclusion that this is an effective approach to learning lines.
Summary
The stimulus can be diagrammed as follows:
Notable Valid Inferences
Temporal art forms must be experienced in a fixed order and over a fixed amount of time.
Temporal art forms are not truly visual.
Truly visual art forms are not temporal.
Truly visual art forms do not require performance
Most art forms are not truly visual.
A
Truly visual art forms do not essentially involve performance.
Must be true. As shown below, if we take the contrapositive of the conditional chain, we see that a truly visual art form does not require performance.
B
Poetry is less like music than it is like painting.
Could be false. We don’t have enough information to compare how similar these art forms are.
C
Spatiality and temporality are mutually exclusive components of art forms.
Could be false. The stimulus does not indicate that spatiality and temporality can never coexist in art.
D
Art forms that must be examined for an extended period of time in order to be understood are essentially temporal.
Could be false. (D) introduces topics that are not included in the stimulus, like understanding (rather than experiencing) art and extended (rather than fixed) periods of time.
E
Anything capable of being performed is either musical or poetic, or both musical and poetic.
Could be false. We know that all performances must be experienced in a fixed order and over a roughly fixed amount of time, but we don’t know that all performances are either musical or poetic––music and poetry are just referenced as two possible examples of performance.
Summary
The stimulus can be diagrammed as follows:
Notable Valid Inferences
If you can measure a the hull of a small boat accurately, then you used a line level.
A
The scientists did not accurately measure the hull’s dimensions because they had no experience measuring hulls.
Could be false. We only know that the scientists weren’t sure they had leveled the hull; we don’t know definitively that they did not do so. Also, we do not have enough information to guarantee the causal claim that (A) makes.
B
The scientists accurately determined the hull’s dimensions, provided that they leveled the hull.
Could be false. (B) can be represented as “level the hull→ measure accurately,” which reverses the sufficient and necessary conditions given in the sitmulus.
C
If the scientists did not accurately determine the hull’s dimensions, it was because they did not have a line level.
Could be false. (C) makes a causal claim that we cannot justify from the information in the stimulus.
D
The scientists were able to accurately record the hull’s dimensions only if they used a line level.
Must be true. We know that using a line tool is a necessary condition of measuring accurately.
E
If the scientists had measured the hull’s dimensions accurately, then at least one of them would have had experience measuring hulls.
Could be false. Experience with measuring hulls isn’t a necessary condition of measuring accurately.
"Surprising" Phenomenon
Why are small rats more likely than normal rats to suffer from heart problems, and large rats are less likely than normal to suffer form heart problems?
Objective
This is an EXCEPT question. The four wrong answers will help differentiate small rats from other rats in a way that makes them more likely to have heart problems, or it will help differentiate large rats from other rats in a way that makes them less likely to have heart problems.
A
Small rats are more likely than large rats to suffer from fatal diseases that tend to strike earlier than do heart problems.
This deepens our confusion. If small rats are more likely than large rats to die before getting heart problems, then we’d expect the overall rate of heart problems among small rats to be lower than for the other rats, who are more likely to survive to the age of getting heart problems.
B
Small rats generally have smaller blood vessels than do large rats, vessels that can more easily be clogged with fatty deposits.
If small rats have smaller blood vessels, which can be more easily clogged with fat, that’s a potential causal mechanism that could explain the smaller rats’ increased risk of heart problems.
C
The larger a rat is, the more successful it will be at defending itself, and therefore the less stressful its existence will be.
The smaller ones have more stress, which might lead to increased heart problems. The larger rats have less stress, which might lead to fewer heart problems. And the average rats are in the middle for stress, which might lead to being in the middle for heart problems.
D
In addition to being the leading cause of weak hearts in adult rats, malnutrition at early stages of development causes rats to be undersized.
This tells us malnutrition causes both a weak heart and smaller body size. This could explain why the smaller rats have more heart problems: those rats were more likely to be the malnourished ones.
E
Although large rats are no more active than rats of average size, they tend to be much more active than small rats, resulting in greater cardiovascular conditioning.
(E) establishes that small rats have less cardiovascular conditioning (meaning conditioning related to the heart) than the average and large rats. This helps explain why small rats have more heart problems than the other groups.