Summarize Argument: Counter-Position
Some people argue that negative news reports on the economy can hurt the economy, because those reports hurt people’s confidence in the economy, which can affect their spending.
The author concludes that negative news reports on the economy don’t hurt the economy, because spending trends correlate closely with people’s confidence in their own economic situations.
Identify and Describe Flaw
The author overlooks the possibility that negative news reports on the economy can decrease people’s confidence in their own economic situations; if this occurs, the reports can still lead to lower spending and damage to the economy.
A
one’s level of confidence in one’s own economic situation affects how one perceives reports about the overall state of the economy
This possibility doesn’t indicate how negative news reports can lead to lower spending. With (A), we have no reason to think that the reports affect confidence in one’s own economic situation.
B
news reports about the state of the economy are not always accurate
The accuracy of reports is irrelevant, because we’re concerned with the effects that reports have on confidence levels in the economy. Reports can affect confidence without being accurate.
C
people who pay no attention to economic reports in the media always judge accurately whether their own economic situation is likely to deteriorate or improve
The argument concerns how news reports can affect people generally. There might be some people who don’t pay any attention to reports in the media; news reports may or may not have effects on people overall, regardless of the existence of people who don’t pay attention to media.
D
people who have little confidence in the overall economy generally take a pessimistic view concerning their own immediate economic situations
(D) points out how news reports might still harm the economy by decreasing people’s confidence in their own economic situations through decreasing confidence in the overall economy.
E
an economic slowdown usually has a greater impact on the economic situations of individuals if it takes people by surprise than if people are forewarned
The comparative effects of a surprise slowdown vs. an expected slowdown has no impact on whether news reports can affect the economy.
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that last year’s mild winter caused this year’s larger-than-usual bird population. This is based on the fact that the mild winter allowed a higher proportion of birds to forage naturally rather than forage at a feeder. In addition, the mild winter also allowed many bird species to avoid having to migrate south during winter, which reduced typical deaths from having to migrate.
Notable Assumptions
The author assumes that there’s no other explanation for why there was a larger-than-usual bird population. The author also assumes that a higher proportion of birds forage naturally rather than by using a feeder is something that is beneficial to bird population.
A
Increases in bird populations sometimes occur following unusual weather patterns.
This doesn’t help establish a causal relationship between a mild winter and the larger bird population. (A) is consistent with a completely coincidental relationship between weather patterns and bird populations.
B
When birds do not migrate south, the mating behaviors they exhibit differ from those they exhibit when they do migrate.
Different mating behaviors have no clear relationship to increased population. In any case, the premises already show how removing the need to migrate south helps increase populations by reducing attrition. We don’t need additional support regarding this aspect of the argument.
C
Birds eating at feeders are more vulnerable to predators than are birds foraging naturally.
This helps establish a causal mechanism between having a lower proportion feeding at bird feeders and a larger population. By allowing a lower proportion to feed at feeders, a mild winter helped protect birds from predators.
D
Birds that remain in their summer range all winter often exhaust that range’s food supply before spring.
If anything, this is something negative about a mild winter. If birds that don’t migrate south often exhaust food supplies before spring, this might suggest a mild winter could make survival more difficult.
E
Birds sometimes visit feeders even when they are able to find sufficient food for survival by foraging naturally.
We know the mild winter allowed a lower proportion to feed at feeders. The fact that some birds might still visit feeders despite not needing to doesn’t change or add to our understanding of the premises and how they relate to the conclusion.
Summarize Argument: Phenomenon-Hypothesis
The number of news stories about small observational studies is larger than the number of news stories about large randomized trials. The author hypothesizes that the reason for this phenomenon is that small observational studies are more likely to have dramatic findings than a large randomized trial. This is based on the fact that newspaper stories tend to report only on studies with dramatic-sounding stories.
Identify and Describe Flaw
The author overlooks alternate explanations for the greater number of stories about small studies. For example, one possibility is that there are simply a greater number of small observational studies than large randomized trials. This is how the overall rate of dramatic findings might be the same between small and large, but we still end up with a greater number of news stories about small studies than large studies.
A
It casts doubt on the reliability of a study by questioning the motives of those reporting it.
The author does not comment on the motives of anyone. Although the author does mention that observational studies are “somewhat unreliable,” he does not suggest that they are unreliable because of the motives of people of people conducting the study or reporting on it.
B
It fails to consider that even if a study’s findings sound dramatic, the scientific evidence for those findings may be strong.
The author’s not concerned with proving whether certain kinds of studies are reliable. So the quality of the evidence is irrelevant. The issue is whether small studies are more likely to have dramatic findings than large ones.
C
It confuses a claim about scientific studies whose findings sound dramatic with a similar claim about small observational studies.
The first sentence claims that newspapers report only on studies with dramatic-sounding results. The second sentence claim stories about small studies are more frequent. These aren’t “similar” claims, but even if they are, the author does not mix up these two claims.
D
It overlooks the possibility that small observational studies are far more common than large randomized trials.
If the small studies are more common than the large ones, that provides an alternate explanation for why there are more news stories about small studies. The greater number of stories doesn’t have to be due to small studies’ having a higher rate of dramatic findings.
E
It fails to rule out the possibility that a study’s having findings that sound dramatic is an effect rather than a cause of the study’s being reported on.
The first line says newspapers tend to report only on studies whose findings sound dramatic. Thus, (E)’s possibility isn’t true. Some studies’ findings sound dramatic. When newspapers choose what to write about, they choose the studies whose findings sound dramatic.
Summarize Argument: Phenomenon-Hypothesis
The microbiologist hypothesizes that the bacteria’s exposure to heavy metals in sewage sludge caused them to develop antibiotic resistance. He supports this by saying that since heavy metals are concentrated in the sludge, bacteria that survive there have evolved to resist heavy-metal poisoning, and these same bacteria are resistant to antibiotics.
Notable Assumptions
The microbiologist assumes that heavy metal exposure can promote antibiotic resistance in certain bacteria. He also assumes that there are no alternative hypotheses to explain the observed correlation— that is, he assumes that there is not a third factor that causes both antibiotic resistance and heavy-metal poisoning resistance. He also assumes that the causal relationship is not reversed— that is, that antibiotic resistance does not cause heavy-metal poisoning resistance.
A
Most bacteria that are not resistant to antibiotics are not resistant to heavy-metal poisoning either.
The microbiologist is only addressing those bacteria that are resistant to both heavy-metal poisoning and antibiotics. Even if (A) is true, it wouldn’t impact his conclusion that heavy-metal exposure causes antibiotic resistance in certain bacteria.
B
Bacteria that live in sewage sludge that is free of heavy metals, but is in other respects similar to normal sewage, are generally resistant to neither heavy-metal poisoning nor antibiotics.
This strengthens the hypothesis by providing a control group. If bacteria in sludge without heavy metals aren’t resistant to heavy-metal poisoning or antibiotics, it’s more likely that the heavy-metal exposure did cause antibiotic resistance in the bacteria in the other sludge.
C
Antibiotic resistance of bacteria that survive in sewage sludge in which heavy metals are concentrated contributes to their resistance to heavy-metal poisoning.
This weakens the microbiologist’s hypothesis by suggesting that the causal relationship is reversed. That is, (C) suggests that antibiotic resistance causes heavy-metal poisoning resistance, rather than the other way around.
D
Sewage sludge that contains high concentrations of heavy metals almost always contains significant concentrations of antibiotics.
This weakens the hypothesis by providing a plausible alternative explanation. If sludge that contains heavy metals also contains significant amounts of antibiotics, it’s likely that the antibiotics cause antibiotic resistance in the bacteria, not the heavy-metal exposure.
E
Many kinds of bacteria that do not live in sewage sludge are resistant to both heavy-metal poisoning and antibiotics.
This doesn’t strengthen the hypothesis that heavy-metal exposure caused antibiotic resistance in the bacteria. We don’t know if the bacteria described in (E) were exposed to heavy metals or not.
Summary
Marital vows often contain a certain promise that uses the word “love.” The author concludes that “love” in this context should not be interpreted as referring to feelings. This is because the promise would make no sense if “love” referred to feelings.
Missing Connection
The conclusion asserts that we should not interpret the word “love” as referring to feelings in the context of a certain promise. But the premises do not establish when one should not interpret a word in a particular way. The premises only establish that interpreting “love” as referring to feelings makes no sense. So to get from the premise to the conclusion, what’s missing is the principle that if an interretation makes no sense, one should not use that interpretation.
A
None of our feelings are within our control.
(A) doesn’t tell us when we should not interpret a word in a particular way. So it cannot establish that we should not interpret “love” as referring to feelings in the context of the promise.
B
People should not make promises to do something that is not within their control.
(B) concerns whether a promise should be made. But the argument concerns whether a certain word in a promise should be interpreted in a particular way. How a word should be interpreted has nothing to do with whether a promise should be made.
C
“Love” can legitimately be taken to refer to something other than feelings.
(C) establishes that “love” can refer to other things besides feelings. But it doesn’t guarantee that we SHOULD NOT interpret “love” as referring to something else besides feelings in the context of the promise.
D
Promises should not be interpreted in such a way that they make no sense.
We know from the premises that interpreting “love” as referring to feelings in the context of the promise makes no sense. (D) establishes that if an interpretation of a promise makes no sense, then we should not use that interpretation. So (D), combined with the premises, proves we should not interpret “love” as referring to feelings in the context of the promise.
E
Promises that cannot be kept do not make any sense.
(E) doesn’t tell us when we should not interpret a word in a particular way. So it cannot establish that we should not interpret “love” as referring to feelings in the context of the promise.