Summarize Argument: Phenomenon-Hypothesis
The researcher concludes that certain makes of car are more common in different regions of the nation. Why? Because the researcher hypothesized that if that conclusion was true, then many people would overestimate the national commonness of their own cars—and this was the very result found by a study, thus supporting the hypothesis.
Identify and Describe Flaw
The researcher concludes that a hypothesis is true based on evidence that supports that hypothesis. However, the hypothesis could still be false, because support for a hypothesis doesn’t guarantee that it’s true. The researcher doesn’t account for the possibility of alternative explanations for the result, for example.
A
The argument fails to estimate the likelihood that most subjects in the experiment did not know the actual statistics about how common their make of car is nationwide.
The likelihood that most of the study participants were unaware of the actual commonness of their make of car is irrelevant to the argument. The argument is about whether different cars are more common in different regions, not about people’s car stats knowledge.
B
The argument treats a result that supports a hypothesis as a result that proves a hypothesis.
The researcher concludes that a hypothesis is true merely based on a premise that supports the hypothesis. This is a flaw because a hypothesis can have some support and still be false, for example if the same evidence is consistent with multiple explanations.
C
The argument fails to take into account the possibility that the subject pool may come from a wide variety of geographical regions.
Whether or not the subject pool comes from a variety of regions isn’t relevant, because the argument’s evidence just depends on most participants overestimating how common their car is.
D
The argument attempts to draw its main conclusion from a set of premises that are mutually contradictory.
The researcher does not use any premises that contradict each other in this argument.
E
The argument applies a statistical generalization to a particular case to which it was not intended to apply.
The argument doesn’t apply a generalization to a particular case. It’s more that the researcher is trying to make a generalization about car distribution across the nation based on a different generalization about how common people think their make of car is.
Summarize Argument
The counselor argues that harsh criticism is necessary to cause someone to change. Why? Firstly, a motive is necessary to cause someone to change. Secondly, unpleasant criticism provides a motive to change, and harsh criticism is unpleasant. This leads to the sub-conclusion that harsh criticism provides a motive to change.
Identify and Describe Flaw
This is a cookie-cutter flaw: confusing necessary and sufficient conditions. The counselor’s premises establish that harsh criticism is sufficient to motivate a change. However, the counselor concludes from this that harsh criticism is necessary for change. The incorrect inference here is that harsh criticism is necessary for motivation (with motivation being necessary for change).
A
infers that something that is sufficient to provide a motive is necessary to provide a motive
The counselor establishes that harsh criticism is sufficient for motivation, but concludes that harsh criticism is necessary for change. We know that motivation is necessary for change, so the conclusion only works by inferring that harsh criticism is necessary for motivation.
B
fails to address the possibility that in some cases the primary goal of criticism is something other than bringing about change in the person being criticized
The counselor isn’t concerned with criticism that has a goal other than bringing about change. The argument only concerns the relationship between types of criticism and change.
C
takes for granted that everyone who is motivated to change will change
The counselor doesn’t claim that motivation is a sufficient condition for change, only a necessary condition.
D
confuses a motive for doing something with a motive for avoiding something
The counselor never brings up or relies on the idea of a motive for avoiding something.
E
takes the refutation of an argument to be sufficient to show that the argument’s conclusion is false
The counselor never considers another argument which has been refuted, and certainly doesn’t claim that the conclusion of a refuted argument is false.
Summarize Argument
The commentator concludes that Acme Engines is liable for the recent wreck. Despite what the company says, Acme Engines must’ve known that knee-height switches were a safety hazard, given that they spent $500,000 to relocate the switches in newer locomotives.
Identify Argument Part
The referenced text is a premise of the argument. It indicates that Acme Engines knew the switches were a safety hazard.
A
proof that the engineer is not at all responsible for the train wreck
The commentator doesn’t claim that the engineer is not at all responsible for the train wreck. We know is that Acme Engines should be held liable, though we don’t know to what extent.
B
a reason for believing that the wreck would have occurred even if Acme Engines had remodeled their older locomotives
We don’t know what would’ve happened if Acme Engines had remodeled their older locomotives. The fact they spent $500,000 remodeling the newer ones simply points to the fact Acme knew the knee-height switches were a safety hazard.
C
an explanation of why the train wreck occurred
The commentator tells us that the wreck happened when a knee-heigh switch was accidentally struck. The fact that Acme Engines spent $500,000 remodeling newer locomotives doesn’t explain the wreck in any further detail.
D
evidence that knee-level switches are not in fact hazardous
If anything, Acme Engines spending $500,000 to remodel new locomotives suggests that knee-height switches might be hazardous. It’s certainly what the commentator concludes, so this seems to contradict the argument.
E
an indication that Acme Engines had been aware of the potential dangers of knee-level switches before the wreck occurred
Since the commentator states Acme Engines wouldn’t have spent $500,000 on a mere inconvenience, it’s implied that $500,000 was spent for a different reason—safety concerns. To address these, Acme would’ve had to have known the hazard the switches posed.
Summarize Argument
The artist concludes that almost everyone in the country wants to be an artist. This is based on the observation that most people the artist knows want to be artists.
Identify and Describe Flaw
This is a cookie-cutter unrepresentative sampling flaw. The artist draws a conclusion about everyone in the country based on an observation about the people the artist knows. But an artist’s social circle is more likely to include people who want to be artists compared to the general public, so their life goals are probably not representative of the goals of the general population of the country.
A
contains a premise that presupposes the truth of the conclusion
The artist’s conclusion is not based on any premises that presuppose or restate the conclusion.
B
presumes that what is true of each person in a country is also true of the country’s population as a whole
The artist doesn’t presume that something that is true of each person in a country is true of the country’s population as a whole.
C
defends a view solely on the grounds that the view is widely held
The artist doesn’t use the popularity of any view as support for a conclusion.
D
bases its conclusion on a sample that is unlikely to accurately represent people in the country as a whole
The argument uses the small sample of the artist’s friends to support its conclusion about the people in the country as a whole. An artist’s friends are not likely to represent the whole country when it comes to the goal of being an artist.
E
fails to make a needed distinction between wanting to be an artist and making a living as an artist
This distinction isn’t necessary to the argument. It’s clear that what the artist is talking about is wanting a career as an artist in either case.
Summary
The qwerty keyboard is the standard for typing devices today. Another keyboard, the Dvorak, would allow people to type faster. But it’s not practical to switch to the Dvorak because the societal costs of switching (time, money, having to learn how to type on a new keyboard) outweigh the benefits gained from faster typing.
Strongly Supported Conclusions
People aren’t typing as fast they could be typing.
Sometimes it’s more practical to keep something that’s the societal standard even if a change could have some benefits.
Sometimes it’s more practical to keep something that’s the societal standard even if a change could have some benefits.
A
Often it is not worthwhile to move to a process that improves speed if it comes at the expense of accuracy.
Unsupported. There’s no suggestion that the Dvorak keyboard is less accurate. Although there are cost associated with frustration of switching to the Dvorak, that doesn’t imply that anyone would be less accurate.
B
People usually settle on a standard because that standard is more efficient than any alternatives.
Unsupported. We don’t know why qwerty became the standard. There’s no suggestion it was the most efficient at the time it was adopted.
C
People often remain with an entrenched standard rather than move to a more efficient alternative simply because they dislike change.
Unsupported. That doesn’t imply people don’t want to switch from qwerty merely because they don’t like change. They might like change, but weigh the costs and benefits of a particular change.
D
The emotional cost associated with change is a factor that sometimes outweighs financial considerations.
Unsupported. The stimulus cites to frustration as one of the costs of switching to Dvorak. That doesn’t imply that the emotional cost of switching by itself outweighs the benefits of faster typing. It’s also not clear that faster typing is a financial consideration.
E
The fact that a standard is already in wide use can be a crucial factor in making it a more practical choice than an alternative.
Strongly supported. Qwerty is the standard. The fact it’s standard increases the costs of switching, because it takes more time and money to switch every keyboard, and people need to learn Dvorak. These costs are an important reason keeping qwerty is more practical.