flaws drill Flashcards
(83 cards)
1
Q
Cereal AD: Fitness experts say that regal excursive is the most effective way to become physically fit, and studies that shown that adults who eat cereal everyday exercise more regularly than adults who do not eat cereal. So by eating Fantastic Flakes every morning, you too will be on the most effective path to physical fitness
A
Infers a cause from a mere correlation.
2
Q
Americans are generally patriotic. So this individual American, Benedict Arnold, was a patriot.
A
infers that some members of a group have a particular characteristic merely from the fact that the group as a whole has it.
3
Q
We studied adult firefighters at a single firestation in a small town. So, we know what all Americans do.
A
Draws a conclusion about all adults from a sample that is too small to be representative
4
Q
Sleeping well contributes to a good LSAT score. So, if you sleep well and do nothing else, you will get a good LSAT score.
A
Infers that a given factor is the sole predictor of a result merely on the grounds that the factor had shown to contribute to that result
5
Q
Committing a burglary makes someone a criminal. So clearly, burglary is necessary to being a criminal. John killed someone, but he didn’t rob them, so John isn’t a criminal.
A
Treats something as merely sufficient to produce a result as if it were necessary to produce that result
6
Q
I could help my neighbor by buying them a lock. So I should buy them one, or I am a bad person.
A
Draws a moral conclusion from evidence that could only support a factual conclusion
7
Q
I got a good performance review yesterday. And yesterday, the performance review I got was bad. So, I will……
A
Bases its conclusion on data that are contradictory
It doesn’t matter what the conclusion is: the data contradict each other.]
8
Q
Lack of trust cause of crime. So clearly, crime is caused by lack of trust.
A
Circular reasoning, asserts in a premise what it is trying to establish in its conclusion
9
Q
A lack of trust in one’s neighbours leads to their lack of respect for the law. A new study provides compelling evidence for this. Neighbourhoods in which people routinely lock their doors have higher burglary rates than neighbourhoods in which people do not routinely lock their doors.
A
Treats what could be the effect of something as if it were the cause of that thing
10
Q
some have argued that body size influences mating decisions throughout all societies. Their argument rests largely on self-reports of university-age students and on analyses of personal advertisements in newspapers for dating partners.
A
Bases a conclusion on a sample that may be unrepresentative of the population about which the the conclusion is properly drawn
11
Q
It is raining, and it is windy. So clearly, the rain is causing the wind.
[Argument made during a hurricane]
A
Concludes that one kind of event causes another kind of event without ruling out the possibility that both kinds of events are the result of a third kind of event.
12
Q
John has listed three reasons why he made his decision. He liked the car, it was cheap, and the car has good reviews. So, clearly, John only bought the car because he liked it. I can’t see any other reason for why he bought it.
A
Concludes that an effect has only once cause in the face of evidence that the effect has multiple causes
13
Q
In this society, people mate frequently. So clearly, this chaste monk from that society must mate frequently.
A
uses s claim that applies only to entire societies to draw a conclusion about individual persons
14
Q
Americans speak loudly all the time. I can say this is true because I met one American, and she spoke loudly.
A
draws a universal conclusion on the basis of a very small number of individual cases
15
Q
Wein claims that keeping animals in zoos is unethical. He points out that it involves placing animals in unnatural environmental merely for the sake of human amusement. However, since Wein sees nothing wrong with owning pets, and keeping pets surely involves placing an animal in unnatural environment merely for human amusement, his claim should be rejected.
A
Rejects a claim merely on the grounds that its proponent holds another view inconsistent with it
16
Q
Weingarten is wrong about zoos. So anyone who argues about zoos is wrong.
A
inappropriately generalizes from a particular case
17
Q
Weingarten says we shouldn’t have zoos. That’s monstrous. How can he be in favor of killing all the animals in zoos?
A
misrepresents the conclusion of the opposing argument
18
Q
To be evil, you must cause harm. Frank caused minor harm today, without meaning to. So, Frank is pure evil.
A
Takes a necessary condition for a practice’s being unethical as a sufficient condition for its being so
19
Q
This person says they are a professor of mathematics. So, when they say 2 + 2 = 5, I know I can trust them. No need to check their diploma.
A
Accepts a view as authoritative without establishing the authority of the source of the view
20
Q
Luck isn’t necessary for success, because success doesn’t need luck.
A
Takes for granted in a premise what it is trying to prove in its conclusion
21
Q
I see successful people often retire early. So, retiring early is the key to success!
A
It treats an effect of something as a the cause of that thing
22
Q
The popular book written by a communist said that luck causes success. I hate communists! So, the book must be wrong.
A
it attacked the source of an argument rather than attacking the substance of that argument
23
Q
Every accountant I’ve worked with has been from Chicago. So all accountants worldwide must be from Chicago.
A
The argument draws a conclusion on the basis of a general statement that has in turn been inferred from a very limited number of particular instances
24
Q
Editorialist: Council members have no proof the plan is safe. So the plan must be unsafe.
A
Confuses the absence of evidence for the claim with evidence against the claim
25
The city council is considering increasing the amount of air traffic allowed at the airport beyond its ordinal design capacity. Several council member say that this increase would not decrease safety as it would be accompanied but he purchase of the lasses safety technology. Both in fact is would decrease safety. Numerous studies conducted 30 years ago show that safety was reduced at every airport where the permitted level of trade was increased beyond the airports ordinal design capacity, even though those airports made use of the latest safety technology.
Fails to consider the possibility that whether an airport can allow more Ari traffic than it was originally designed for without reducing safety depends largely on what the latest technology is.
26
A nonprofit organization concerned with a social issue sent out a fund-raising letter to 5,000 people. The letter was accompanied but a survey soliciting recipient's opinions. Of the 300 respondents, 283 indicated in the survey that they agreed with the organization's position on the social issue. This suggests that most of the 5,000 people to whom the letter was sent agreed with that position.
Draws a conclusion about a population form observations of a subgroup that is quite likely to be unrepresentative of that population in certain relevant respects.
27
We conducted a survey where we promised $100 to anyone who said they liked us. 100% of people said they liked us, so we must be very popular.
It relies on the accuracy of a survey made under conditions in which in which it is probably that most of the responses to that survey did not correctly reflect the opinions of the respondents
28
Most Americans dislike the president. So the president’s family must also dislike the president.
Uses evidence about an opinion held by the majority of a population in an attempt to justify a conclusion regarding the opinion of a small part of that population
29
In a recent field study of prairie pants, the pant species in a prairie plot had, the more vigorously the plants grew and the better the soil retained nutrients. Thus, having more plant species improves a prairie's ability to support plant life.
Infers of two correlated phenomena, X and Y, that X causes Y without considering whether Y causes X
Correlation/ cause
30
I looked at two prairie plants growing in my backyard. This lets me make conclusions about all prairie plants in North America.
bases a general conclusion on data that is likely to be unrepresentative
31
Increase in number = 10 more, increase in proportion = 10% more. They’re pretty obviously different: 10% of America, for example is around 33 million people, which is a lot more than 10 people.
Takes an increase in bomber to indicate and increase in proportion
32
Researchers recently studied the relationship between diet and mood, using a diverse sample of 1,000 adults. It was found that those who ate the most chocolate were the most likely to feel depressed. Therefore, by reducing excessive chocolate consumption, adults can almost certainly improve their mood.
Cit draws a conclusion about a causal relationship between two phenomena from evidence that merely suggests that there is a correlation between those phenomena
33
Those with a chocolate allergy had less depression when they stopped eating chocolate. So everyone is likely to have less depression when they stop eating chocolate
It draws a conclusion about the population as a whole on the basis of the sample that is unlikely to representative of that population.
34
If John was planning to murder me, then John would live in the same city I do. John does live in the same city I do, so he must be planning to murder me!
It confuses a condition that is necessary for establishing the truth of the conclusion with a condition that is sufficient for establishing the truth of the conclusion.
35
There are already more great artworks in the world than any human being could appreciate in a lifetime, works capable of satisfying virtually any taste imaginable. Thus, contemporary artists, all of whom believe that their works enable many people to feel more aesthetically fulfilled than they otherwise could, are mistaken.
Overlooks the possibility that the work of at least one of the contemporary artist is appreciated by many people whose access to the great majority of other artwork is severely restricted
36
Politician: Union leaders argue that increases in multinational control of manufacturing have shifted labor to nations without strong worker protections, resulting in a corresponding global decrease in workers' average wages. Given that these leaders have vested interest in seeing wages remain high, they would naturally want to convince legislator to oppose multination control. Thus, legislation should reject this argument.
Ad Hominem.
| Treats circumstances potentially affecting the union leaders' argument as sufficient to discredit those leaders argument
37
John says that the sky is blue. But John is a union member, so he must be wrong.
Treats a mere fact that certain people are union member as sufficient to cast doubt on all of the view points expressed by those people
38
John is arguing for puppy protection laws, because John wants to help puppies. Since I can discern John’s motives, he must be wrong.
Presumes, without justification, that anyone whose political motivations are clearly discernible is an unreliable source of information to the legislator.
39
The union leaders gave a piece of evidence. Therefore, that must be all of their evidence.
Presumes, without justification, that the argument it cities is the unions leaders' only argument for their view
40
Some union leaders argue against multinational control. So every single union leader on planet Earth must agree.
Presumes, without evidence, that leaders of all unions argue against increases in multinational control of manufacturing
41
Scholar: Recently, some religions have updated the language of the traditional text and replaced traditional rituals with more contemporary ones. These changes have been followed by increases in attendance at places of worship affiliated with these religions. This shows that any such modernization will result in increased numbers of worship.
Lacked justification: Correlation/ Cause
The modernization of religious texts and rituals of some religious was the cause of their increases in attendance
With any correlation, there are four possibilities:
Reform causes attendance.
Anticipated attendance causes reform
A third cause (A charismatic new Pope?) leads to both reform and attendance
It’s a coincidence
42
A person's personality is linked to that person's genes. And since a person's genes do not ordinarily change over time, it follows that a person's personality remains unchanged with the passing of time.
There are two problems with this argument:
It assumes that genes are the only factor that affects personality.
It assumes that something can’t change just because it was initially created a certain way.
43
Activists: Medical conditions such as cancer and birth defects have been linked to pollutants in water. Organic pollutants such as dioxins, and inorganic pollutants such as mercury, are ingested but fish as they move up the food chain to people, where they have accumulated in tissue. Since most cancers and birth defects are incurable, we need to aim at their prevention. Clearly, the only effective way to significantly reduce the overall incidence is to halt industries known to produce these pollutants, given that such industries are unlikely to comply adequately with strict environmental regulation.
Fails to consider the possibility that a significant number of occurrences of cancer and birth defects may be caused by presentable factors other than industrial pollutants.
44
The more people watch basketball, the more the newspaper covers basketball. So newspaper coverage must cause people to watch basketball.
Correlation/ Cause
45
I surveyed Bob, the runner, over whether running was popular. Bob says yes, and so did the running coach. So running must be popular.
bases a conclusion on a sample that is too small
46
Running is popular because it’s a popular sport.
Circular reasoning,
Employs a premise the contention it purports to show
47
The newspaper editor claims they provide fair coverage. But the editor smells bad! Clearly, their coverage is unfair.
Ad hominem
48
Your newspaper's advertisement claims that you provide coverage of high schools most popular sports. Clearly this is false advertising. Of the schools's students, 15 % compete on the track team, while only 5% of the students play basketball. Hence, track is far more popular than basketball, yet track gets no coverage and basketball gets full-page coverage.
misinterpret a key word in the newspaper's advertisement
From a fair reading of the ad, it’s pretty clear the newspaper meant “most popular to watch” and not “most popular to participate in”.
49
Several movie critics have claimed that this movie will inspire people to act in socially irresponsible ways, yet this claim relies entirely on survey data that have turned out to be deeply flawed. Thus these critics have made a claim that is not only untrue but also potentially harmful to the moviemakers' reputation.
Infers a claim is false merely on the grounds that no satisfactory evidence for it has been offered
50
The critics dress badly and smell like sewage.
Ad hominem
51
Data indicated that 30% of the houses in our town have inadequate site drainage and 30% have structural defects that could make them unsafe. Hence, at least 60% of our town's houses have some kind of problem that threatens the integrity.
Overlooks the possibility
Some of the houses that have structural defects that could make them unsafe also have inadequate site drainage
52
A good manager must understand people and be able to defuse tense situations. But anyone who is able to defuse tense situations must understand people. Since Ishiko is able to defuse tense situations, she must be a good manager.
Confuses qualities necessary for being a good manager with qualities that guarantee being a good manager
53
The government has recently adopted a policy of publishing airline statistics, including statistics about each airline's number of near collisions and its fines for safety violations. However, such disclosure actually undermines the government's goal of making the public more informed about airline safety, because airlines will be much less likely to give complete reports if such information will be made available to the public.
Fails to consider that, even if the reports were incomplete, they may nevertheless provide the public with important information about airline safety
54
People ought to take into account a discipline's blemished origins when assessing the scientific value of that discipline. Take, for example, chemistry. It must be considered that many of its landmark results were obtained by alchemists—a group whose superstitions and appeals to magic dominated the early development of chemical theory.
Fails to consider how chemistry's current theories and practices from those that the alchemists mention
55
Linguist: Only if a sentence can be diagrammed is it grammatical. Any grammatical sentence is recognized as grammatical by speakers of its language. Speaker X's sentence can be diagrammed. So, speaker X's sentence will be recognized as grammatical by speakers of its language.
fails to consider the possibility that some ungrammatical sentences are diagrammable
56
Television allows us to transmit images of ourselves that propagate into space. The earliest of these transmissions have by now reached all of our neighboring star systems. None of these transmissions, so far as we know, has been recognized; we have yet to receive any messages of extraterrestrial origin. We must conclude that there is no extraterrestrial intelligence in any of our neighboring star systems.
Infers that there is no extraterrestrial intelligence in neighbouring star system from the lack of proof that there is
57
Professor: The economic measures proposed by our country's ruling party will result in windfall profits for a particular sector of our economy. But no economic measures should be approved unless they benefit our economy as a whole. So the proposed measures should not be approved.
overlooks the possibility that economic measures that result in windfall for one sector of the economy are also beneficial to the economy as a whole
58
Letter to the editor: According to the latest proposal, building the new highway in our district will involve a loss of some of our richest farmland. In spite of this loss, most residents of our district will surely support the proposal. After all, numerous polls have indicated that the residents in our district unanimously agree that a new highway in our district is necessary.
It presumes that agreement of desirability of a goal implies agreement about the desirability of a particular means of attaining that goal
59
A region wherein all telephone numbers now have the same area code is being split into two regions, each with its own area code. Since the residential section of the region has more telephone numbers than does the section containing mostly businesses, the residential section should keep the old area code and the business section should get the new area code. After all, this will result in fewer incidents of dialing the wrong number than the reverse distribution of area codes.
Overlooks the possibility that businesses typically receive more phone calls than residence
60
John: For 40 years, fluoride has been added to public drinking water. According to a study, fluoridated public drinking water when given to laboratory rats causes bone cancer. Ninety percent of all the male rats in the test sample were affected, but the female rats were unaffected. Even though I am healthy now, I should nevertheless stop drinking fluoridated water; only then will I be sure not to develop bone cancer.
John does not consider the possibility of other causes of bone cancer.
61
Lawyer: If you take something that you have good reason to think is someone else's property, that is stealing, and stealing is wrong. However, Meyers had no good reason to think that the compost in the public garden was anyone else's property, so it was not wrong for Meyers to take it.
takes a condition that by itself is enough to make an action wrong to also be necessary in order for that action to be wrong
The argument says stealing is always wrong but it doesn't mean that an action that isn't stealing isn't wrong
62
Airport administrator: According to the latest figures, less than 1 commercial flight in 2 million strays off course while landing, a number low enough to allow runways to be built closer together without a significant increase in risk. Opponents of closer runways claim that the number is closer to 1 in 20,000, but this figure is based on a partial review of air traffic control tapes and so is relatively unreliable compared to the other figure, which is based on a thorough study of the flight reports required of pilots for all commercial flights.
The argument overlooks the fact that those who make mistakes are often unreliable sources of information about those mistakes
63
Researcher: People who participate in opinion surveys often give answers they believe the opinion surveyor expects to hear, and it is for this reason that some opinion surveys do not reflect the actual views of those being surveyed. However, in well-constructed surveys, the questions are worded so as to provide respondents with no indication of which answers the surveyor might expect. So if a survey is well constructed, survey respondents' desire to meet surveyors' expectations has no effect on the survey's results.
overlooks the possibility that the answers can be influenced by beliefs about the surveyors expectations even if those beliefs are unfounded
64
Commentator: The Duke of Acredia argued long ago that only virtuous Acredian rulers concerned with the well-being of the people will be able to rule successfully. Since then, when Acredian governments have fallen, their falls have always been during the rule of one who viciously disregards the people's needs. The Duke, then, was right about at least one thing: Concern for the welfare of the people is necessary for the successful governance of Acredia.
infers that a certain condition is required for success from the fact that the lack of that condition is associated with failure
65
Every-time we lost our basketball game, my favourite referee was absent. So, my favourite referee must be absent in order for us to win
infers that a certain condition is required for success from the fact that the lack of that condition is associated with failure
its possible they were losing the games due to free throws being missed etc.
66
A recent magazine article argued that most companies that do not already own videoconferencing equipment would be wasting their money if they purchased it. However, this is clearly not true. In a recent survey of businesses that have purchased such equipment, most of the respondents stated that the videoconferencing equipment was well worth its cost.
unrepresentative sample
67
Consumer advocate: Manufacturers of children's toys often place warnings on their products that overstate the dangers their products pose. Product-warning labels should overstate dangers only if doing so reduces injuries. In fact, however, manufacturers overstate their products' dangers merely for the purpose of protecting themselves from lawsuits brought by parents of injured children. Therefore, manufacturers of children's toys should not overstate the dangers their products pose.
The argument relies on a unjustified assumption that an action has an effect only if it was preformed in order to bring about that effect
68
Sarah, who is an excellent mechanic, said that in her opinion the used car John is considering is in good mechanical condition. However, it is clear that Sarah cannot be trusted to give an honest opinion, since when Emmett asked her opinion of his new haircut she lied and said she thought it looked good. Therefore, it is very likely that Sarah also lied in giving her opinion of the mechanical condition of that car.
it bases a sweeping claim on the evidence provided by an instance that is clearly irrelevant
69
Large discount chains can make a profit even while offering low prices, because they buy goods in large quantities at favorable cost. This creates a problem for small retailers. If they try to retain their customers by lowering prices to match those of large discount chains, the result is a lower profit margin. But small retailers can retain their customer base without lowering prices if they offer exceptional service. Hence, small retailers that are forced to compete with large discount chains must offer exceptional service in order to retain their level of profitability.
exceptional service is not the sole reason customer prefer small retailers
70
The consequences of surgical errors can be devastating, and no one would want to risk surgery unless it was performed by someone highly competent to perform surgery. General surgeons have special training and expertise that make them extremely competent to perform surgery. Therefore, surgery at the hands of anyone other than a general surgeon involves highly undesirable risks.
General surgeons are not the only ones competent to preform surgery
71
Marion knows that the bridge on her usual route is closed and that, unless she takes the train instead of driving, she can get to work on time only by leaving at least 45 minutes early. She must go to her neighborhood bank before leaving for work, however, and the bank will not be open in time for her to do so if she leaves 45 minutes early. Therefore, since she hates taking the train, Marion cannot avoid being late for work.
treats evidence that someone will adopt a certain course of action as though that evidence excluded the possibility of an alternative course of action
72
A successful chess-playing computer would prove either that a machine can think or that chess does not involve thinking. In either case the conception of human intelligence would surely change.
a successful chess playing computer would not model a human approach to chess playing
73
Mary to Jamal: You acknowledge that as the legitimate owner of this business I have the legal right to sell it whenever I wish. But also you claim that because loyal employees will suffer if I sell it, I therefore have no right to do so. Obviously, your statements taken together are absurd.
Overlooks the possibilities that Jamal is referring to two different kinds of rights
74
Taylor: From observing close friends and relatives, it is clear to me that telepathy is indeed possible between people with close psychic ties. The amazing frequency with which a good friend or family member knows what one is thinking or feeling cannot be dismissed as mere coincidence.
fails to address a highly plausible alternative explanation for all instances of the observed phenomena
75
Camille: Manufacturers of water-saving faucets exaggerate the amount of money such faucets can save. Because the faucets handle such a low volume of water, people using them often let the water run longer than they would otherwise.
Rebecca: It is true that showering now takes longer. Nevertheless, I have had lower water bills since I installed a water-saving faucet. Thus, it is not true that the manufacturers' claims are exaggerated.
Rebecca takes for granted?
She saved as much on her water bill as the manufacturers' claims suggested she would
76
Ecologist: One theory attributes the ability of sea butterflies to avoid predation to their appearance, while another attributes this ability to various chemical compounds they produce. Recently we added each of the compounds to food pellets, one compound per pellet. Predators ate the pellets no matter which one of the compounds was present. Thus the compounds the sea butterflies produce are not responsible for their ability to avoid predation.
infers, from a claim that no individual member of a set has a certain effect, that the set as a whole does not have that effect
77
Bowers: A few theorists hold the extreme view that society could flourish in a condition of anarchy, the absence of government. Some of these theorists have even produced interesting arguments to support that position. One writer, for example, contends that anarchy is laissez-faire capitalism taken to its logical extreme. But these theorists' views ignore the fundamental principle of social philosophy—that an acceptable social philosophy must promote peace and order. Any social philosophy that countenances chaos, i.e., anarchy, accordingly deserves no further attention.
the meaning of a key term shifts illicitly during the course of the argument
Anarchy--> Absence of government
social philosophy
78
Quality control investigator: Upon testing samples of products from our supplier that were sent by our field inspectors from various manufacturing locations, our laboratory discovered that over 20 percent of the samples were defective. Since our supplier is contractually required to limit the rate of defects among items it manufactures for us to below 5 percent, it has violated its contract with us.
Overlooks the possibility that the field inspectors tend to chose items for testing that they suspect are defective
79
Dietitian: To control blood cholesterol by dietary means, consuming oils low in saturated fats is much more effective than merely limiting dietary cholesterol. All oils that are solid at room temperature are high in saturated fats, but canola, an excellent high-temperature cooking oil, is liquid at room temperature. Thus, it is a good oil to use for those who wish to control their blood cholesterol.
takes for granted that a certain characteristic that normally accompanies another characteristic is present only if it accompanies by that other characteristic
an oil must be a must be solid at room temperature in order be to high in saturated fats
80
Undoubtedly, one's freedom is always worth the risk of losing one's life. Consider a person who is locked in a bare cement room with no hope of escape. This person is not really living and has nothing to lose.
generalizes inappropriately from a single extreme case to a universal claim
81
Many professional economists describe economics as a science. Sciences, however, are by definition non-normative: they describe but they do not prescribe. Yet economists are often called on to recommend a course of action for governments and financial institutions. Therefore, since economists play a prescriptive role in society, economics should not be thought of as a science.
Fails to recognize the significant distinction between a discipline and the people who work in that discipline
82
Voting records regularly shows that people over 65 vote in the highest percentages while young adults are leas likely to vote. This indicates that citizens are becoming increasingly disconnected from the political system with each passing generations
Comparison Flaw
Compares an early stage of one generation to a later state of another
83
Politicians often advocate increased overall economic productivity while ignoring its drawbacks. For example, attempting to increase the productivity of a corporation means attempting to increase it profitability, which typically leads to a reduction in the number of workers employed by that corporation. Thus, attempting to increase productivity in the economy as a whole may benefit business owners, but will increase the number of employed workers.
Comparison Flaw
Fails to justify its presumption that attempting to increase productivity in the economy as a a whole would produce results similar to those produced by attempting to increase productivity in a single corporation.
