Summarize Argument
The author concludes that Cotrell can only write average quality magazine articles. She supports this by saying that any superior articles by Cotrell must be plagiarized, because Cotrell can only write average quality articles.
Identify and Describe Flaw
This is the cookie-cutter flaw of circular reasoning, where the author’s conclusion is simply a restatement of a premise. In this case, the author concludes that Cotrell can only write average quality articles based on the premise that his superior articles must be plagiarized because he can only write average quality articles.
A
It simply ignores the existence of potential counterevidence.
The author actually discusses potential counterevidence: Cotrell’s few superior articles. She dismisses this evidence by saying that the articles must have been plagiarized, but she doesn’t ignore the existence of counterevidence.
B
It generalizes from atypical occurrences.
The author doesn’t generalize from atypical occurrences. Instead, she draws a specific conclusion about Cotrell based on all of Cotrell’s articles— the superior ones and the average ones.
C
It presupposes what it seeks to establish.
The author seeks to establish that Cotrell can only write average quality articles. In order to do so, she presupposes that he can only write average quality articles.
D
It relies on the judgment of experts in a matter to which their expertise is irrelevant.
The author never mentions or relies on the judgement of any experts.
E
It infers limits on ability from a few isolated lapses in performance.
The author does infer limits on Cotrell’s writing ability. But she does so based on his average work and the claim that his superior work was plagiarized, not based on “a few isolated lapses in performance.”
Summarize Argument
The author concludes that scientific experiments should use double-blind techniques. To support this recommendation, the author says that double-blind techniques help prevent misinterpretations that can come from pre-existing expectations or opinions. Further, the author says that scientists should try to avoid misinterpretations. So since double-blind techniques help avoid misinterpretations, scientists should use these techniques.
Identify Conclusion
The conclusion of the argument is that scientific experiments should use double-blind techniques: “Double-blind techniques should be used whenever possible in scientific experiments.”
A
Scientists’ objectivity may be impeded by interpreting experimental evidence on the basis of expectations and opinions that they already hold.
This information is offered as a premise. This information supports the recommendation to use double-blind techniques, because those techniques prevent the mis-interpretations that can come from pre-existing expectations and opinions.
B
It is advisable for scientists to use double-blind techniques in as high a proportion of their experiments as they can.
This is the conclusion. The author is recommending the use of double-blind techniques; the rest of the argument serves as support for this idea. This is a paraphrase of the first sentence of the argument, which is the conclusion.
C
Scientists sometimes neglect to adequately consider the risk of misinterpreting evidence on the basis of prior expectations and opinions.
The information in this answer could be understood as a reason that double-blind studies are beneficial, but the idea of scientists neglecting to consider the risk of misinterpretations is not explicitly mentioned in the argument. This is not the conclusion.
D
Whenever possible, scientists should refrain from interpreting evidence on the basis of previously formed expectations and convictions.
This is not a paraphrase of the first line of the argument, so it is not the main conclusion. Further, this idea is offered as support for the main conclusion, so it is a premise
E
Double-blind experimental techniques are often an effective way of ensuring scientific objectivity.
This information is a premise that supports the conclusion. This information is offered as a reason that double-blind techniques should be used: Because these techniques are effective in ensuring objectivity, we should use them.
Summarize Argument: Phenomenon-Hypothesis
The author concludes that Fred’s computer mouse must have been unplugged. He supports this by saying that unplugging the mouse from a computer causes all programs that require the mouse to become unusable. He then notes that a software program on Fred’s computer that requires the mouse has become unusable.
Identify and Describe Flaw
This is the flaw of mistaking sufficiency for necessity. The author treats “unplugging the mouse” as necessary for “the program becoming unusable.” But according to his argument, “unplugging the mouse” is sufficient, not necessary.
In other words, the argument overlooks the possibility that Fred’s program could become unusable without his mouse becoming unplugged.
A
It contains a shift in the meaning of “unusable” from “permanently unusable” to “temporarily unusable.”
This is the cookie-cutter flaw of “equivocation.” But the author doesn’t use multiple meanings of the word “unusable” throughout his argument. He simply uses it to mean that a software program has stopped working.
B
It treats an event that can cause a certain result as though that event is necessary to bring about that result.
Unplugging the mouse can cause a program to become unusable, but the author assumes that it’s necessary to bring about that result. In other words, the conclusion mistakenly treats “unplugging the mouse” as a necessary condition, while in the premises, it’s merely sufficient.
C
It introduces information unrelated to its conclusion as evidence in support of that conclusion.
The author never introduces unrelated information as evidence. His evidence is related to his conclusion, but he mistakes the sufficient condition for a necessary condition.
D
It attempts to support its conclusion by citing a generalization that is too broad.
The argument cites a specific scenario about Fred, not a broad generalization.
E
It overlooks the possibility that some programs do not require a peripheral component such as a mouse.
The author is only addressing Fred’s software program that does require a mouse. Presumably other programs don’t require a mouse, but those programs aren’t relevant to the argument.
Summary
Twelve healthy people with version 1 of a gene and twelve healthy people with version 2 of a gene at a standard diet supplemented with high-cholesterol food. High cholesterol is associated with increased risk of heart disease. After three weeks of this diet, people with version 1 of the gene had increased cholesterol, whereas people with version 2 of the gene did not have increased cholesterol.
Strongly Supported Conclusions
Version 2 of the gene might help remove cholesterol from the body. Eating high-cholesterol foods does not always lead to increased cholesterol in the body.
A
Approximately half the population carries a gene that lowers cholesterol levels.
Unsupported. We don’t know the proportion of the general population with version 2 of the gene. The stimulus never told us that the participants in the study were representative of the general population.
B
Most of those at risk of heart disease may be able to reduce their risk by adopting a low-cholesterol diet.
Unsupported. We know high cholesterol increases risk of heart disease, but most people with heart disease might not have high cholesterol. They might have heart disease for other reasons.
C
The bodies of those who have the Apo-A-IV-2 gene excrete cholesterol when blood cholesterol reaches a certain level.
Unsupported. We know the people with version 2 of the gene did not exhibit increased cholesterol. We don’t know whether this has anything to do with storing cholesterol before excreting it.
D
The presence of the Apo-A-IV-1 gene seems to indicate that a person has a lower risk of heart disease.
Unsupported. We don’t know the respective risks of heart disease among the two groups. In any case, people with version 1 of the gene ended up with increased cholesterol, so there’s evidence version 1 may be at higher risk of heart disease than version 2.
E
The presence of the Apo-A-IV-2 gene may inhibit the elevation of blood cholesterol.
Strongly supported. The people with version 2 of the gene didn’t end up with increased cholesterol, whereas people with version 2 did. This is evidence something about version 2 may be reducing cholesterol or counteracting the increased cholesterol we would expect to observe.
For clarity, sentence two expresses the main point of the passage. In the video, I drew the "premise line" too high up making it seem like sentence two is a premise when it is not.