Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that owning a VCR prompts people to go to the movie theater more. She bases this on a correlation: people who tend to go to the movies more often also own a VCR.
Identify and Describe Flaw
This is a cookie-cutter “correlation does not imply causation” flaw, where the author sees a positive correlation and jumps to the conclusion that one thing causes the other, without ruling out alternative hypotheses. Specifically, she overlooks two key alternatives:
(1) The causal relationship could be reversed—maybe going to movies more causes people to get VCRs, not the other way around.
(2) Some other, underlying factor could be causing the correlation—maybe there’s something that causes people to both go to the movies and buy VCRs. (Maybe they simply like movies in general?)
A
concludes that a claim must be false because of the mere absence of evidence in its favor
The author doesn’t bring up a lack of evidence for any claims. Rather, she reaches her conclusion by presenting evidence in the form of a correlation.
B
cites, in support of the conclusion, evidence that is inconsistent with other information that is provided
The only evidence cited is a correlation between people who own VCRs and people who go to the movies more often. Everything else in the stimulus is at least consistent with this correlation being true.
C
fails to establish that the phenomena interpreted as cause and effect are not both direct effects of some other factor
This describes a key alternative hypothesis that the author ignores. She fails to establish that VCR ownership and moviegoing are not both direct effects of some other, underlying causal factor. (Maybe they’re both effects of simply liking movies in general?)
D
takes a condition that by itself guarantees the occurrence of a certain phenomenon to be a condition that therefore must be met for that phenomenon to occur
This is the cookie-cutter flaw of mistaking a sufficient condition for a necessary one. The author doesn’t make this mistake, and her argument doesn’t rely on conditional reasoning. Instead, she uses causal reasoning (and overlooks possible alternative hypotheses in the process).
E
bases a broad claim about the behavior of people in general on a comparison between two groups of people that together include only a small proportion of people overall
This is the cookie-cutter flaw of overgeneralization. But the author doesn’t generalize from a limited sample to an overly broad conclusion. Rather, she compares all people who own VCRs to all people who don’t, and so considers all people overall.
Summarize Argument: Counter-Position
This is an usual stimulus because there’s no argument. Instead, we have a claim and a reply to that claim.
Attorneys’ claim: The government destroyed evidence that would have supported the defendant.
Government’s reply: There is presently no evidence that supports the defendant.
Notable Assumptions
There are no assumptions, because there’s no argument here. But notice that the government’s reply doesn’t actually address the point made by the attorneys. The attorneys’ point is that there was once supporting evidence, before it was destroyed. But the government’s response is all about the present situation—there’s now no supporting evidence. This leaves open the possibility that the attorneys are right: the government destroyed the evidence, which is why it no longer exists.
A
It leaves open the question of whether the government had destroyed such evidence.
The government’s reply is all about the present situation—there’s now no supporting evidence. This is completely consistent with the attorneys’ claim that there was once evidence, but the government destroyed it. So the question remains: did the government destroy that evidence?
B
It establishes that the attorneys’ charge is an exaggeration.
The attorney’s charge is all about what happened in the past, while the government’s reply is solely about the present situation. So, the government’s reply does nothing to counter the attorneys’ charge.
C
It shows that the attorneys did not know whether their charge was true.
The attorney’s charge is all about what happened in the past, while the government’s reply is solely about the present situation. So, the government’s reply does nothing to counter the attorneys’ charge.
D
It demonstrates the government’s failure to search for evidence in its files.
The government’s reply might be true—there might currently be no evidence in the government’s files (or anywhere else) to support the defendant. We don’t know. So we can’t conclude that the government failed to search for evidence.
E
If true, it effectively disproves the charge made on behalf of the defendant.
The attorney’s charge is all about what happened in the past, while the government’s reply is solely about the present situation. So, even if the government’s reply is true, it does nothing to counter the attorneys’ charge.
Summary
The argument concludes that ABC Company should implement a flextime schedule in order to increase production. As support, the argument cites studies which have shown that flextime schedules improve morale.
Notable Assumptions
The argument goes from a premise stating that flextime improves morale to a conclusion that flextime would increase production. This depends on the assumption that an improvement in morale could lead to an increase in production.
A
the employees who prefer a flextime schedule are the most productive employees at ABC Company
Knowing about employees’ preferences isn’t necessary to establish a relationship between morale and production. This could be false without affecting the strength of the argument.
B
an increase in the morale of ABC Company’s employees could lead to increased production
Based on the claim that flextime improves morale, the argument concludes that flextime would increase production. This only makes sense if we assume that increasing morale could lead to increased production.
C
flextime schedules tend to be associated with reduced lateness and absenteeism
Even if this were not the case, it wouldn’t undermine the argument. A decrease in lateness and absenteeism isn’t necessary for morale to affect production.
D
employees are most productive during the part of the day when all employees are present
The argument wouldn’t be affected if this were not assumed—the argument just depends on morale affecting production, not the exact reason why. So, this isn’t necessary.
E
companies that are in competition with ABC Company also use a flextime schedule
The choices of competing companies aren’t essential to establish the argument’s support structure, making this unnecessary.
Summarize Argument
The argument’s conclusion is that a piece of candy made with X grams of cane sugar has no more calories than a piece of fruit containing X grams of fructose. This is based on the claim that cane sugar and fructose have the same amount of calories per gram.
Identify and Describe Flaw
The argument’s conclusion is about an overall property of candy and fruit, based on evidence about only one ingredient of candy and one component of fruit. In other words, the argument ignores the possibility that candy could have other ingredients that make it higher in calories than fruit, even though cane sugar and fructose have equivalent calorie counts.
A
fails to consider the possibility that fruit might contain noncaloric nutrients that candy does not contain
Whatever noncaloric nutrients fruit or candy contain, that’s irrelevant to this argument, which is only about calorie counts.
B
presupposes that all candy is made with similar amounts of sugar
The argument is limited to the hypothetical situation of a piece of candy and a piece of fruit with the same amount of sugar. It’s irrelevant whether real candies are made with varying amounts of sugar.
C
confuses one kind of sugar with another
The argument clearly distinguishes cane sugar and fructose, and never confuses them.
D
presupposes what it sets out to establish, that fruit does not differ from sugar-based candy in the number of calories each contains
The argument doesn’t presuppose its conclusion, but instead supports it with evidence about the caloric density of different sugars.
E
overlooks the possibility that sugar might not be the only calorie-containing ingredient in candy or fruit
The argument comes to a conclusion about the relative calories of candy and fruit based on evidence only about the types of sugar each one contains. However, if candy or fruit have other calorie-containing ingredients, the conclusion is thrown into question.
Keziah: You have misunderstood. The government has always spent far more, per user, from general revenue sources to fund highways than to fund mass transit. The additional revenue from the gasoline tax will simply allow the government to make its distribution of transportation funds more equitable.
Summarize Argument
Keziah concludes the proposed gasoline tax will allow the government to distribute transportation funds more equitably. As evidence, she points out that the government has always spent more from general revenue sources to fund highways compared to mass transit.
Describe Method of Reasoning
Keziah provides important context in order to support the idea that the proposed gasoline tax is fair. She does this by describing that historically, government funding for highways has been disproportionate compared to funding for mass transit. Since taxpayers in general have always paid more in favor of drivers, the gasoline tax will make funding more equitable by evening-out the tax burden.
A
elaborating the context of the issue in order to place the proposal in a more favorable light
The context is the fact that government has always spent more from general revenue resources to fund highways. With this context, the gasoline tax appears more fair and equitable.
B
appealing to the principle that what benefits society as a whole benefits all individuals within that society
Keziah does not appeal to this principle. Instead, she describes that funding for highways has always been unfairly supported by the general revenue fund, and the gasoline tax is meant to make this burden more equitable.
C
challenging the presupposition that fairness is an appropriate criterion on which to judge the matter
Keziah does accept fairness as an appropriate criterion. Contrary to Lambert, she believes the gasoline tax is actually a more equitable way to fund mass transit networks.
D
demonstrating that the proposed tax increase will not result in increased expenses for drivers
Keziah concedes that the gasoline tax will result in increased expenses for drivers. For Keziah, though, she believes that this is a more equitable way to fund mass transit networks.
E
declining to argue a point with someone who is poorly informed on the matter under discussion
Keziah does not make any claim that Lambert is poorly informed on the issue.
Summarize Argument
The author concludes that Sara definitely does not have a strep infection, despite having some symptoms of one. Why? Because Sara has the same symptoms as Michael, and the two of them play together every day. This leads to the sub-conclusion that Sara probably has the same illness as Michael. And Michael definitely doesn’t have a strep infection.
Identify and Describe Flaw
The author draws a conclusion about what must definitely be the case based on evidence about what is probably the case. The conclusion is that Sara “definitely” doesn’t have strep, because Michael definitely doesn’t have strep. However, Sara and Michael only “probably” have the same illness.
A
presupposes what it sets out to prove
The author doesn’t presuppose that Sara doesn’t have strep—this conclusion is reached based on evidence about Sara’s symptoms matching with those of her playmate Michael, who doesn’t have strep.
B
mistakes the cause of a particular phenomenon for the effect of that phenomenon
The author isn’t making any claims about cause and effect.
C
fails to distinguish between acute streptococcal infections on the one hand, and less severe streptococcal infections on the other
The difference between acute and less severe strep infections isn’t relevant to the argument—the question is just whether Sara might have strep, not what type of strep she might have.
D
treats evidence that the conclusion is probably true as if that evidence establishes the certainty of the conclusion
The author reaches the conclusion that Sara definitely doesn’t have strep based on evidence that Sara probably has the same non-strep illness as Michael.
E
makes a general claim based on particular examples that do not adequately represent the respective groups that they are each intended to represent
The author never makes a general claim about any groups based on examples taken to be representative. The argument is just about individual children, groups are irrelevant.
Summarize Argument
The author concludes that if a survey is well constructed, survey respondents’ desire to meet surveyors’ expectations won’t affect the survey’s results. This is based on the fact that in well-constructed surveys the way questions are worded don’t indicate the kind of answer that the surveyor might expect.
Identify and Describe Flaw
The author overlooks the possibility that a respondents’ answers can still be affected by desire to meet the surveyor’s expectations, even if the questions don’t indicate the surveyor’s expectations. Perhaps, for example, the respondent might form a belief about the surveyor’s expectations through other aspects of the survey besides the questions.
A
an opinion survey that disguises the surveyor’s expectations may be flawed in a number of ways, some of which have nothing to do with the surveyor’s expectations
The conclusion is only concerned with whether the desire to meet expectations will affect the results. Whether there are other ways a survey can be flawed doesn’t affect whether the desire to meet expectations will affect results in a well-constructed survey.
B
when people who respond to opinion surveys hold strong opinions, their answers are unlikely to be influenced by other people’s expectations
(B) points out the possibility that respondents’ answers are UNlikely to influenced. This doesn’t point out a flaw, because we’re trying to show why respondents’ views still CAN be affected by the surveyor’s expectations.
C
many opinion surveyors have no expectations whatsoever regarding the answers of people who respond to surveys
This possibility doesn’t undermine the argument’s reasoning. If many surveyors have no expectations, that doesn’t help show why respondents’ desire to meet expectations actually could affect results.
D
some people who know what answers an opinion surveyor expects to hear will purposefully try to thwart the surveyor’s expectations
The conclusion concerns whether a desire to MEET expectations will affect survey results. The desire to “thwart” expectations involves a desire NOT to meet expectations; this is about a different issue that the conclusion isn’t concerned with.
E
the answers of opinion-survey respondents can be influenced by beliefs about the surveyor’s expectations even if those beliefs are unfounded
This possibility shows how a desire to meet expectations can still affect the results, even if the questions don’t indicate the expectations. The respondent might just wrongly assume what the surveyor expects, and answer in a way that meets those assumed expectations.