Summarize Argument: Counter-Position
The author concludes that the belief that perception and memory are significantly reduced by age 80 is false. She supports this with a recent study showing no difference in the abilities of 80-year-olds and 30-year-olds to play a card game that tests perception and memory.
Identify and Describe Flaw
The author assumes that perception and memory aren't greatly reduced by age 80 simply because 80-year-olds performed just as well as 30-year-olds on the card game. However, she doesn't consider that the game might only test basic levels of perception and memory. If the game requires only a low level of these abilities, the author can't conclude that perception and memory aren't reduced by age 80.
A
the study’s card game does not test cognitive abilities other than perception and memory
This doesn’t impact the argument, so failing to consider it can’t be a flaw. Because the argument only addresses perception and memory, whether the card game tests other cognitive abilities is irrelevant.
B
card games are among the most difficult cognitive tasks one can attempt to perform
We don’t know if this general statement about card games applies to the particular card game designed to test perception and memory. But even if it does, (B) might strengthen the argument by suggesting that 80-year-olds are just as good as 30-year-olds at such a difficult task.
C
perception and memory are interrelated in ways of which we are not currently aware
This doesn’t impact the argument, so failing to consider it can’t be a flaw. The card game showed similar levels of perception and memory between 80-year-olds and 30-year-olds. Whether perception and memory are connected in unknown ways doesn’t affect this outcome.
D
the belief that 80-year-olds’ perception and memory are reduced results from prejudice against senior citizens
Even if this is true, it doesn't point out a flaw in the author’s argument because she’s trying to disprove this belief.
E
playing the study’s card game perfectly requires fairly low levels of perception and memory
The author fails to consider the possibility that the game might only test basic levels of perception and memory. If this is true, then the game would reveal very little about the levels of perception and memory in 80-year-olds vs. in 30-year-olds.
Attorney: I ask you to find Mr. Smith guilty of assaulting Mr. Jackson. Regrettably, there were no eyewitnesses to the crime, but Mr. Smith has a violent character: Ms. Lopez testified earlier that Mr. Smith, shouting loudly, had threatened her. Smith never refuted this testimony.
Summarize Argument
The attorney concludes that Mr. Smith should be found guilty of assaulting Mr. Jackson. She supports this by saying that Ms. Lopez testified that Mr. Smith loudly threatened her and he never refuted her testimony, so Mr. Smith has a violent character.
Identify and Describe Flaw
The attorney makes many unwarranted assumptions in her argument. She assumes that just because Smith loudly threatened Lopez, he must have a violent character, and that just because he has a violent character, he’s guilty of assaulting Jackson.
She also assumes that just because Smith never refuted Lopez’s claim that he threatened her, her claim must be true.
Note the questions stem: “The attorney’s argument is fallacious because it reasons that ____.” The correct answer will fill in this blank with an assumption made by the attorney.
A
aggressive behavior is not a sure indicator of a violent character
The attorney does not reason that aggressive behavior is not a sure indicator of a violent character. Instead, she assumes that Smith’s aggressive behavior (his alleged loud threat) is a sure indicator of his violent character.
B
Smith’s testimony is unreliable since he is loud and aggressive
The attorney doesn’t bring up any of Smith’s testimony at all, nor does she assume that it’s unreliable.
C
since Smith never disproved the claim that he threatened Lopez, he did in fact threaten her
This points out one of the attorney’s fallacious assumptions. She assumes that, because Smith didn’t refute Lopez’s claim, her claim must be true. She uses this to argue that Smith has a violent character and thus committed the crime.
D
Lopez’s testimony is reliable since she is neither loud nor aggressive
The attorney supports Lopez’s testimony by saying that it was never refuted. She doesn’t assume that Lopez’s testimony is reliable because Lopez isn’t loud or aggressive.
E
having a violent character is not necessarily associated with the commission of violent crimes
The question stem asks for an answer in terms of what the argument reasons. In contrast to (E), “the attorney’s argument is fallacious because it reasons that” having a violent character is necessarily associated with the commission of violent crimes.
Summarize Argument
The author concludes that B.t. toxins are better for managing insect pests than chemical insecticides. Why? Because particular B.t. toxins will kill only particular species, leaving other insects, birds, and mammals unharmed.
Notable Assumptions
The author assumes that chemical pesticides do not target particular species effectively in the same way as B.t. toxins. She assumes there is no other property of B.t. toxins that makes them less effective or more risky than chemical insecticides in practice.
A
Chemical insecticides cause harm to a greater number of insect species than do B.t. toxins.
This is irrelevant without knowing whether the species harmed are common pests. If B.t. toxins cause damage only to pest insects, but chemical insecticides cause damage to harmless insects, then the argument is strengthened.
B
No particular B.t. toxin is effective against all insects.
This doesn’t mean there is any insect for which no B.t. toxin is effective. It’s possible that every pest insect can be targeted with the appropriate B.t. toxin.
C
B.t. toxins do not harm weeds that do damage to farm crops.
This is irrelevant without information about whether chemical insecticides do the same. If neither substance does damage to such weeds, this offers no contrast.
D
Insects build up resistance more readily to B.t. toxins than to chemical insecticides.
This is a reason why B.t. toxins may be less effective than chemical insecticides in practice. Despite their advantages, B.t. toxins are more likely to be repelled by genetic resistance, and thus less likely to work.
E
Birds and rodents often do greater damage to farm crops than do insects.
This states no difference between B.t. toxins and chemical insecticides that would suggest B.t. toxins are less effective or riskier than chemical insecticides. The author does not say the use of chemical insecticides harms mammals or birds.
Summarize Argument
The author concludes that it is unlikely that bureaucracies will be simplified. As a premise to support this claim, the author says that bureaucracies are designed to resist change.
Identify Argument Part
The referenced text acts as a premise to support the author’s main conclusion. It gives a reason that it is unlikely that bureaucracies will be simplified.
A
It is a premise offered in support of the claim that it is unlikely that bureaucracies will be simplified.
This answer accurately identifies the referenced text as a premise, and it correctly identifies what claim the premise is supporting, so this is the correct answer.
B
It is a conclusion for which the only support offered is the claim that dissatisfaction with complex bureaucratic systems is growing.
The referenced text is a premise, not a conclusion, so this answer is not correct.
C
It is cited as evidence that bureaucratic systems are becoming more and more complex.
The referenced text does not support the claim about the growing dissatisfaction with complex bureaucratic systems. Further, the argument does not claim that bureaucracies are becoming more complex; it says that dissatisfaction with the complexity is growing.
D
It is used to weaken the claim that bureaucracies should be simplified.
The argument does not claim that bureaucracies should be simplified; it only says that they are unlikely to be simplified even though there is growing dissatisfaction with their complexity. Further, the referenced text is used to support the conclusion, not to weaken a claim.
E
It is a conclusion for which the claim that bureaucracies are unlikely to be simplified is offered as support.
The referenced text is a premise, not the conclusion, so this is not the answer.
Summarize Argument
The author concludes that it is not correct to believe that the surest way to increase the overall correctness of a set of one’s beliefs is to never change the set, except by rejecting a belief when given adequate evidence against it. This is based on the author’s assertion that, if one were to follow that approach, then over time, one would have fewer and fewer beliefs. But, we need many beliefs in order to survive. (The implication is that following the approach described would threaten our ability to survive.)
Identify and Describe Flaw
The author’s premises establish that following the approach described threatens our ability to survive. But that doesn’t show that the approach isn’t the surest way to increase the overall correctness of one’s set of beliefs. Why can’t the surest way to increase overall correctness also threaten our survival?
A
presumes, without providing any justification, that the surest way of increasing the overall correctness of the total set of one’s beliefs must not hinder one’s ability to survive
The author assumes that the fact the approach described hurts our ability to survive shows that it’s not the surest way to increase overall correctness. (A) captures the author’s assumed connection between hurting survival and the surest way to increase overall correctness.
B
neglects the possibility that even while following the statisticians’ rule, one might also accept new beliefs when presented with some kinds of evidence
The statisticians’ rule does not allow for accepting new beliefs. So the author doesn’t overlook this possibility.
C
overlooks the possibility that some large sets of beliefs are more correct overall than are some small sets of beliefs
The author never takes a position on whether larger sets of beliefs are more or less correct than smaller sets. The possibility in (C), if true, would not undermine the author’s reasoning.
D
takes for granted that one should accept some beliefs related to survival even when given adequate evidence against them
The author never takes a position on what one “should” do. The argument is simply about whether a particular approach is the surest way to increasing overall correctness of beliefs. What one should believe or not believe doesn’t affect the reasoning.
E
takes for granted that the beliefs we need in order to have many beliefs must all be correct beliefs
The argument concerns the overall correctness of a set of beliefs and the need for many beliefs to survive. Perhaps some beliefs can be false within a set of many beliefs; this doesn’t undermine the reasoning.
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that about 3 million years ago, the Antarctic ice sheet must temporarily have melted. This is based on the fact that we recently discovered 3-million-year-old fossils under the ice sheet of Antarctica. These fossils are of a kind that have only been found in ocean-floor sediments. In addition, severe climatic warming or volcanic activity in Antarctica’s mountains could have melted the ice sheet, which would have produced liquid water that submerged the area.
Identify and Describe Flaw
The author assumes there’s no way for the fossils to be found under the ice sheet unless the ice sheet was melted. This overlooks other explanations for the presence of the fossils. Perhaps, for example, the floor has shifted underneath the ice sheet, which allowed the fossils to move underneath when they were originally not underneath the ice sheet.
A
That a given position is widely believed to be true is taken to show that the position in question must, in fact, be true.
The author’s conclusion that the ice sheet must have melted is not based on the idea that this view is widely believed to be true. We don’t know whether other people besides the author believe the ice sheet melted.
B
That either of two things could independently have produced a given effect is taken to show that those two things could not have operated in conjunction to produce that effect.
The author does not assume that the melting of the ice sheet could not have been produced by a combination of climatic warming and volcanic activity. The author presents those two things as potential causes for the melting, but never suggests they were mutually exclusive.
C
Establishing that a certain event occurred is confused with having established the cause of that event.
The author’s conclusion is that a certain event occurred — the ice sheet melted. The flaw relates to the author’s failure to prove that this event happened. The author did not establish this event occurred, and does not try to reach a conclusion about the cause of this event.
D
A claim that has a very general application is based entirely on evidence from a narrowly restricted range of cases.
The claim that the ice sheet must have temporarily melted does not have “general application.” It is a claim about a particular ice sheet and that it must have melted around 3 million years ago. This does not apply to other ice sheets or other time periods.
E
An inconsistency that, as presented, has more than one possible resolution is treated as though only one resolution is possible.
The inconsistency is that we found 3-million-year-old fossils under the ice sheet, even though this kind of fossil has previously been found only in the ocean floor. The author thinks this must be because the ice sheet melted. This overlooks other explanations.
Summarize Argument
The linguist looks to certain studies purporting to show that bilingual children tend to have a smaller vocabulary and concludes that these studies are deeply flawed. As evidence, the linguist states that vocabulary tests were only given in one language. Dual-language tests show children often expressed a given concept with a word from only one of their two languages.
Describe Method of Reasoning
The linguist shows that the studies are deeply flawed by pointing out a significant error in their methodology. If the children were given tests in only one language, then the tests are flawed because dual-language tests show children often express concepts with words from only one of their two languages.
A
offering evidence for the advantages of bilingualism over monolingualism
The linguist does not compare the advantages and disadvantages between bilingualism and monolingualism. The linguist’s argument does not address children who are monolingual.
B
pointing out an inconsistency in the view that bilingualism overstresses a child’s linguistic capabilities
The linguist does not describe a contradiction with this viewpoint. Instead, the linguist provides additional information relevant to evaluating the integrity of the studies that support this viewpoint.
C
offering evidence that undermines the use of any vocabulary test to provide information about a child’s conceptual map
The linguist only disfavors a specific kind of vocabulary test. We cannot assume that the linguist would disfavor any vocabulary test. In fact, the linguist seems to view dual-language tests somewhat favorably.
D
providing a different explanation for the apparent advantages of bilingualism from the explanation suggested by the results of certain studies
The linguist does not address any advantages of bilingualism. The linguist’s argument seeks to counter the viewpoint of bilingual children having a disadvantage, but this is not the same as describing the advantages of bilingualism.
E
pointing out a methodological error in the technique used to obtain the purported evidence of a problem with bilingualism
the methodological error in technique is administering a vocabulary test in only one language. The evidence of the problem with bilingualism is the evidence that bilingual children have a smaller vocabulary and thus reduced conceptual map.
Summarize Argument: Counter-Position
The researcher argues that the psychological problems of children of divorced parents may not be caused by the children’s difficulty adjusting to their parents’ divorce. Instead, the researcher proposes an alternative explanation: the children learn divorce-related bad behavior from their parents. This bad behavior could then be the cause of the children’s problems. By offering an alternative explanation, the researcher supports the conclusion that children’s psychological problems may not be caused by difficulty adjusting.
Identify Argument Part
The assertion that children of divorced parents have a higher rate of psychological problems is given as a known phenomenon that the researcher explains through learned behavior rather than through difficulty adjusting to divorce.
A
It is the conclusion of the argument.
The argument’s conclusion is that children’s problems aren’t necessarily caused by difficulty adjusting. The assertion that children of divorced parents have more problems is just given as a fact; it isn’t supported by anything, so can’t be a conclusion.
B
It is the claim that the argument tries to refute.
The researcher accepts that children of divorced parents have more problems. The argument is instead trying to refute the idea that the problems are caused by difficulty adjusting to the divorce.
C
It is offered as evidence for the claim that divorce is harmful to the children of the divorcing parents.
The researcher never claims that divorce is harmful to children. If anything, the argument implies that problems are caused by the parents’ pre-divorce behavior, not the divorce itself.
D
It is offered as evidence for the claim that certain behaviors are often responsible for divorce.
The claim that certain behaviors can lead to divorce is presented as a fact without any support. Also, the claim about children of divorced parents having psychological problems doesn’t support any other claim in the argument: it’s context.
E
It is cited as an established finding for which the argument proposes an explanation.
This is the role played by the claim that children of divorced parents have more psychological problems. It’s taken as a fact, and the researcher explains it with learned behavior.