We start with the question stem: Which of the following most accurately expresses the main conclusion of the argument? This is a Main Conclusion question.

The stimulus begins by stating, “Baumgartner’s comparison of the environmental hazards of gasoline-powered cars with those of electric cars is misleading.”

Ok, that sure sounds like a claim that I need to be convinced of. If this is the Main Conclusion, then the argument will give premises to support that idea. The author then goes on to say that “Baumgartner examines only production of the cars, whereas it is the product's total life cycle - production, use, and recycling - that matters in determining the environmental impact.” Ok, that definitely Supports the idea that Baumgartner is misleading. You can’t compare the two books by looking only at the first chapter; you need to compare the entirety of the book. Similarly, you can’t compare cars by looking only at production; you need to look at production + use + recycling. Baumgartner made an error by only looking at a small piece of the puzzle, the production, when you actually need to examine more. This is a reason why Baumgartner’s comparison is misleading.

The author doesn't think you should take his word for it that production and use, and recycling should be considered. He provides evidence for the claim by saying that a typical gasoline-powered car both consumes more resources and pollutes more than an electric car. So the idea that gas cars consume more and pollute more are Minor Premises that support the Sub Conclusion that we should consider production, use, and recycling to determine environmental impact. The Sub Conclusion supports the Main Conclusion that Baumgartner’s comparison is misleading when he only evaluated a small piece, the production, of the larger environmental impact puzzle. Since our job is to identify the Main Conclusion, we can now go to the answer choices to figure out which one expresses the same idea.

Correct Answer Choice (A) While saying that “Baumgartner makes a deceptive comparison between the environmental hazards of gasoline-powered and electric cars” is slightly more pointed, it gets at the idea that the comparison is misleading. This is the correct answer.

Answer Choice (B) is a minor premise that supports the sub conclusion in Answer Choice (D). Since this is a Main Conclusion question, both of these are wrong.

Answer Choice (C) is a popular trap answer choice, the trap being “inaccurate data.” A test-taker who picks this answer realizes that the author is saying that Baumgartner’s evidence is insufficient, but the test-taker inaccurately assumes that it is because the data is inaccurate. Does the author charge Baumgartner with using inaccurate data? No. The author simply claims that the data Baumgartner uses is not the full story. Take a shot every time the author is inaccurate jeez.

Answer Choice (E) is not the Main Conclusion, and even worse, it’s an assumption. Earlier, we discussed how we actually do not know the environmental impact of gas vs. electric cars. All we know is that gas cars consume more and pollute more. We do not know if producing gas-powered cars is more environmentally hazardous than producing electric cars. While the author does argue Baumgartner’s analysis of production is misleading, we do not know the way it is misleading. Is it a matter of degree? Does Baumgartner think producing gas-powered cars is less environmentally damaging? Does the author think producing gas-powered cars is less environmentally damaging? The answer to all of these questions is “maybe.”


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A recent study involved feeding a high-salt diet to a rat colony. A few months after the experiment began, standard tests of the rats’ blood pressure revealed that about 25 percent of the colony had normal, healthy blood pressure, about 70 percent of the colony had high blood pressure, and 5 percent of the colony had extremely high blood pressure. The conclusion from these results is that high-salt diets are linked to high blood pressure in rats.

Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that high-salt diets are linked to high blood pressure in rats. This is due to an experiment showing most rats fed a high-salt diet had high blood pressure after a few months.

Notable Assumptions
The author assumes that the correlation between high-salt diets and high blood pressure constitutes a link. This means the author doesn’t believe the high blood pressure was entirely caused by some third factor. This also means the author believes that the rat colony didn’t have the same proportion of rats with high blood pressure before starting the high-salt diets.

A
How much more salt than is contained in a rat’s normal diet was there in the high-salt diet?
We know these are high-salt diets. We don’t need to know exactly how much less salt a rat’s normal diet contains.
B
Did the high blood pressure have any adverse health effects on those rats that developed it?
We’re not interested in the effects of high blood pressure. We care about the link between high-salt diets and high blood pressure in rats.
C
What percentage of naturally occurring rat colonies feed on high-salt diets?
We don’t care about how common high-salt diets are. We care about the link between those diets and high blood pressure.
D
How many rats in the colony studied had abnormally high blood pressure before the study began?
If the same proportions of rats had high blood pressure before the high-salt diet versus after the high-salt diet, then the link between such diets and high blood pressure is greatly weakened. If not, then high-salt diets would seem to be linked with high blood pressure.
E
Have other species of rodents been used in experiments of the same kind?
We’re not interested in other rodents. We’re only concerned with the link between high-salt diets and high blood pressure in rats.

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Detective: Bill has been accused of committing the burglary at the warehouse last night. But no one saw Bill in the vicinity of the warehouse. So we must conclude that Bill did not commit the burglary.

Summarize Argument: Counter-Position
The detective concludes that Bill did not commit the warehouse burglary last night. The basis for this conclusion is that no one saw Bill near the scene of the crime.

Identify and Describe Flaw
This is the cookie-cutter flaw of mistaking an unsupported conclusion for a false one. In this case, while we don’t have enough evidence to conclude that Bill was guilty, we can’t jump from that to definitively conclude that he was innocent.

For example, perhaps he is guilty, but no one saw him because he stealthily evaded detection after committing the crime.

A
treats evidence that is irrelevant to the burglar’s identity as if it were relevant
The detective doesn’t do this—eyewitness evidence of the burglar’s identity is relevant.
B
merely attacks the character of Bill’s accusers
This is the cookie-cutter flaw of ad hominem (attacking the source); it isn’t applicable here because the detective doesn’t say anything about the accusers’ character.
C
fails to provide independent evidence for the theory that Bill committed the burglary
Since the conclusion is that Bill did not commit the burglary, failing to provide evidence that he did commit it could not possibly be the flaw in the argument.
D
treats a lack of evidence against Bill as if it exonerated Bill
This is the cookie-cutter flaw of mistaking a lack of support for a false conclusion. The detective notes that one form of evidence that would prove a theory (Bill’s guilt) true is missing. He erroneously concludes from that that the theory must be false.
E
fails to establish the true identity of the burglar
The detective doesn’t need to establish the true identity of the burglar to conclude that Bill isn’t the burglar.

The question stem reads: The reasoning in the Detective's argument is most vulnerable to criticism on grounds that the argument… This is a Flaw Question.

The Detective begins by saying Bill was accused of burglarizing a warehouse last night. The Detective then claims that no one saw Bill in the vicinity of the warehouse last night. Using that claim as evidence, the Detective concludes that Bill must not have committed the burglary. Right off the bat, we can see that this argument is flawed.

When evaluating an argument, our job is to be agnostic. That means we have to start with no position on a conclusion. If I make an argument that fails to prove that x is true, all you can conclude is that I have failed to prove that x is true. You cannot claim that x is false. So just because I lack evidence for a claim, that does not mean the claim is false. Turning back to the Detective, we do not have any witnesses to prove that Bill was burglarizing the warehouse. So all we know is that the Detective has no witnesses. That does not mean Bill didn't burglarize the warehouse. Maybe Bill is a ninja. Maybe the warehouse is located in a community for the blind. Maybe there was simply no one near the warehouse who could have witnessed the crime. If Bill robs a warehouse and no one is there to see it, did Bill really commit a burglary? You get the point. Let's move to the answer choices.

Answer Choice (A) is wrong because the fact that no one saw Bill near the warehouse is relevant to the identity of the Burglarer. It is just not enough to say that Bill is not the burglar.

Answer Choice (B) is wrong because there is no attack on the character of the witnesses. If the Detective made an argument, "Everyone who claims to have seen Bill near the warehouse is a known Bill-haters, therefore Bill must not have robbed the warehouse," then (B) would look better.

Answer Choice (C) is wrong because the Detective argues that Bill did not commit the burglary.

Correct Answer Choice (D) is what we discussed. The Detective does treat a lack of evidence that Bill robbed the warehouse as if it exonerates Bill (which means Bill didn't rob the warehouse).

Answer Choice (E) is incorrect. The Detective does not need to establish the true identity of the burglar in order to prove Bill did not commit the robbery. He just needs better evidence. For example, if the Detective could show that Bill was in a different state during the time of the crime, he could exonerate Bill without establishing the burglar's identity.


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Psychologist: Because of a perceived social stigma against psychotherapy, and because of age discrimination on the part of some professionals, some elderly people feel discouraged about trying psychotherapy. They should not be, however, for many younger people have greatly benefited from it, and people in later life have certain advantages over the young—such as breadth of knowledge, emotional maturity, and interpersonal skills—that contribute to the likelihood of a positive outcome.

Summarize Argument: Counter-Position
The psychologist argues that elderly people should not be discouraged about trying psychotherapy. He supports this claim with the fact that younger people have benefitted from psychotherapy. He then claims that older people’s greater knowledge, maturity, and interpersonal skills mean that they are even more likely to benefit from psychotherapy than younger people.
The psychologist does give some reasons why some elderly people may be reluctant to try psychotherapy (social stigma against the treatment and age discrimination) but these reasons provide context for the idea that the psychologist is arguing against.

Identify Conclusion
The psychologist claims that, although elderly people may feel discouraged against psychotherapy, “they should not be.”

A
Certain psychotherapists practice age discrimination.
This is context. This claim provides a potential explanation for why elderly people may be discouraged about trying psychotherapy, but our psychologist is arguing that they should not feel discouraged. This answer gives support for the idea that the psychologist argues against.
B
Elderly people are better able to benefit from psychotherapy than are younger people.
This is a premise for why elderly people should not be discouraged about trying psychotherapy. This fact gives them more of a reason to try psychotherapy.
C
Elderly people should not be reluctant to undergo psychotherapy.
This is the conclusion. This claim is supported by the facts that many younger people have benefitted from psychotherapy, and older people may be more likely to have a positive outcome.
D
Characteristics associated with maturity are important factors in psychotherapy’s success.
This is a premise that lends support to the claim that elderly people should not be discouraged about trying psychotherapy.
E
Elderly people are less inclined to try psychotherapy than are younger people.
We actually don’t know this from the argument. We only know that some elderlhy people are discouraged about trying psychotherapy, and that many younger people have benefitted it. We don’t have enough information to compare the two groups’ inclinations in trying psychotherapy.

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