Summary
Most people who invest don’t do their own research. Of this group, some rely on their broker and others on instinct. A minority of people who invest conduct their own research. Of this group, some occasionally do their own research, while others always do their own research. Most people (of all those who invest) make a profit.
Notable Valid Inferences
Less than half of the people who invest in the stock market do their own research. Some people who don’t do their own research make a profit.
A
Some people who make a profit on their investments in the stock market do so without doing any research of their own.
This must be true. If most people who invest don’t do any research, and most people who invest also profit, there must be some people who belong to both groups. In other words, there must be overlap, as both groups encompass more than half of all people who invest.
B
Most people who invest in the stock market either rely solely on their broker or make decisions based merely on hunches.
This could be false. Most people who invest don’t do their own research; of this majority, some rely on their broker and others on hunches. There could be a third sub-group that relies on something other than a broker or hunches. We can’t assume these are the only sub-groups.
C
Some people who do investment research on their own, while just as often relying on their broker or on hunches, make a profit in the stock market.
This could be false. We don’t know how large the group of people who do some research while also relying on brokers or hunches is, but we do know they belong to the minority of people who do their own research. They could also be in the minority who don’t profit.
D
Most people who invest in the stock market without doing any research of their own make a profit.
This could be false. We know some people who invest without doing research make a profit—we have no reason to believe most of them do.
E
Most people who rely solely on their broker rather than on hunches make a profit in the stock market.
This could be false. We know most people who invest don’t do their own research: within this group, some people make a profit and some rely solely on their broker. We don’t know if these groups overlap and how many people (if any) who rely solely on their broker make a profit.
A
there may be many forms of dangerous radiation other than X-rays and the kinds of radiation absorbed by members of commercial airline flight crews
Other forms of dangerous radiation are irrelevant. The author is only concerned with the dangers of radiation from commercial airline flights and dental X-rays.
B
receiving a dental X-ray may mitigate other health risks, whereas flying does not
Whether X-rays or flights may mitigate other health risks is irrelevant. The argument only focuses on the dangers of radiation put out by flights and X-rays.
C
exposure to X-rays of higher intensity than dental X-rays may be harmful
Higher-intensity X-rays are irrelevant. The argument is only concerned with the radiation put out by dental X-rays and flights.
D
the longer and the more often one is exposed to radiation, the more radiation one absorbs and the more seriously one is harmed
The author fails to consider this. If members of commercial flight crews go on a lot of flights, the low levels of nearly harmless radiation they absorb on each flight could eventually add up and harm them.
E
flying at high altitude involves risks in addition to exposure to minor radiation
Risks posed by altitude are irrelevant. The author just argues that radiation from commercial flights poses little danger to commercial flight crews.
Summarize Argument
The author concludes more funding should be directed toward intervention research in order to explore a cost-effective way to help people predisposed to mental disorders. Why? Because more research is needed to confirm some existing research—which found that early intervention can mitigate risk factors for mental disorders—and to develop practices for care based on those results.
Notable Assumptions
The author assumes the care practices developed will be cost-effective while addressing risk factors for mental disorders. She assumes more funding for intervention research will be directed towards the “comprehensive research program” described, that more funding is required for such a program, and that such a program is necessary to confirm the findings of the limited research.
A
Most minor mental disorders are more expensive to treat than other minor health problems.
This doesn’t affect the argument. The author implies a comparison between the cost of treating early risk factors for mental disorders and the cost of treating more-fully-developed mental disorders, not between minor mental disorders and other, unrelated health problems.
B
Prevention research can be coordinated by drawing together geneticists, neurologists, and behavioral scientists.
This explains how the research program might be organized, not why it’s necessary to confirm the results of the existing research. It’s possible the previous research also included input from geneticists, neurologists, and behavioral scientists.
C
Reducing known risk factors for mental disorders is relatively inexpensive compared to the long-term treatment required.
This makes concrete the author’s main assumption, that treating risk factors early is more cost-effective than treating full-blown disorders later. It justifies her advocacy for funding in order to develop those treatments.
D
Current funding for intervention research is now higher than it has ever been before.
This compares past funding with present funding, while the author compares present funding with future funding. She argues funding should increase to support the program described—she makes no claim about the present level of research funding relative to past levels.
E
Once a mental disorder disappears, there is a fair chance that it will recur, given that complete cures are rare.
This doesn’t affect the argument. There’s no indication that current care practices or the ones to be developed will cause mental disorders to disappear—only that they might help prevent those disorders from developing.
The increasing complexity of scientific inquiry has led to a proliferation of multiauthored technical articles. Reports of clinical trials involving patients from several hospitals are usually coauthored by physicians from each participating hospital. Likewise, physics papers reporting results from experiments using subsystems developed at various laboratories generally have authors from each laboratory.
Summary
The increasing complexity of scientific inquiry has caused a proliferation of multiauthored technical articles. Reports of clinical trials with patients from several hospitals are usually coauthored by physicians from each hospital. Physics papers reporting results from experiments using subsystems developed at several laboratories usually have authors from each laboratory.
Notable Valid Inferences
Most reports of clinical trials with patients from several hospitals are coauthored.
Most physics papers reporting results from experiments using subsystems developed at several laboratories are coauthored.
A
Clinical trials involving patients from several hospitals are never conducted solely by physicians from just one hospital.
Could be false. To say that these clinical trials are never conducted by a sole physician is too extreme. We know that these trials are usually conducted by multiple physicians, but this does not mean that all of them are.
B
Most reports of clinical trials involving patients from several hospitals have multiple authors.
Must be true. We know that most of these reports have multiple authors because the stimulus tells us that usually these reports are coauthored by physicians from each participating hospital.
C
When a technical article has multiple authors, they are usually from several different institutions.
Could be false. The information in the stimulus is restricted to certain clinical trials and physics papers. Applying this idea to all technical articles generally is too extreme.
D
Physics papers authored by researchers from multiple laboratories usually report results from experiments using subsystems developed at each laboratory.
Could be false. This answer choice reverses the relationship in the stimulus. The stimulus tells us that usually physics papers about experiments using subsystems developed at each laboratory have authors from each laboratory.
E
Most technical articles are authored solely by the researchers who conducted the experiments these articles report.
Could be false. The information in the stimulus is restricted to certain clinical trials and physics papers. Applying this idea to all technical articles generally is too extreme.
Summarize Argument: Counter-Position
The author takes on a claim by vegetarians that there are two individually sufficient reasons for not eating meat. The author presents a hypothetical that would make it unclear if the second reason is actually individually sufficient. If eating meat is essential to good health, it becomes unclear if empathy for other conscious creatures is a sufficient reason to not eat meat.
Identify Argument Part
This is a hypothetical premise used to demonstrate that it is not clear if an aversion to living at the expense of other conscious creatures is a sufficient reason to stop eating meat.
A
It is used to disprove the vegetarian position that we should not eat meat.
This inaccurately identifies the position being disputed. The author is weakening the idea that there are two individually sufficient reasons for not eating meat, not that we should avoid meat.
B
It is used to show that the two types of reasons cited in favor of vegetarianism are independent.
The supposition actually shows that the two types of reasons are somewhat dependent. The second reason doesn’t hold up as well if the first reason is failed. Therefore, they are interconnected.
C
It is used to disprove the claim that a vegetarian diet is healthy.
The author is presenting a hypothetical premise, not actually disputing the health of vegetarianism.
D
It is used to weaken the claim that the consciousness of animals is a sufficient reason for not eating meat.
By presenting this supposition, the individual strength of this reason for not eating meat is weakened. It shows that this reason may not be completely sufficient.
E
It is used to show that there is no sufficient reason for not eating meat.
The author is weakening one of two potentially sufficient reasons. The first reason remains sufficient in this argument.
Summary
In theory, analog systems are better than digital systems. This is because analog signals can be infinitely detailed, whereas digital signals cannot, since they can’t be more precise than their digital units. But there’s an associated disadvantage of analog systems. Since there’s no limit to the level of detail in analog signals, duplication of analog signals allows room for variations from the original (called errors), which tend to build up as the analog signal is further duplicated. At some point, the number of errors in an analog signal makes it impossible to understand the information contained in the original signal.
Strongly Supported Conclusions
When duplicated, digital signals allow for less variation than analog signals allow.
Digital systems may be better for signals that must be duplicated many times.
Digital systems may be better for signals that must be duplicated many times.
A
Many ideas that work well in theory do not work well in practice.
Unsupported. Analog systems are at a disadvantage when signals have to be copied many times. That doesn’t imply that analog systems don’t work well in practice.
B
Analog representation of information is impractical because we do not need infinitely detailed information.
Unsupported. The stimulus doesn’t suggest that we don’t need infinitely detailed information. Maybe we do, and it would be better for us if there were a way to achieve such infinite detail.
C
Digital systems are the best information systems because error cannot occur in the emission of digital signals.
Unsupported. Although digital systems are not as prone to error in duplication as are analog systems, that doesn’t imply that there are never any errors associated with emission of digital signals.
D
Analog systems are inferior to digital systems for most practical purposes.
Unsupported. Although analog systems are worse for purposes that involve duplicating a signal many times, that doesn’t imply they’re worse for “most” practical purposes. Maybe most practical purposes don’t involve numerous copies.
E
Digital systems are preferable to analog systems when the signal must be reproduced many times.
Strongly supported. We’re told that analog systems lead to a build-up of errors in the signal when the signal is copied many times. Digital system don’t have this problem to the same extent. So, digital systems are preferable when we need the signal to be copied many times.