The dwarf masked owl, a rare migratory bird of prey, normally makes its winter home on the Baja peninsula, where it nests in the spiny cactus. In fact, there are no other suitable nesting sites for the dwarf masked owl on the Baja peninsula. But a blight last spring destroyed all of the spiny cacti on the Baja peninsula. So unless steps are taken to reestablish the spiny cactus population, the dwarf masked owl will not make its home on the Baja peninsula this winter.

Summary
The argument concludes that the dwarf masked owl will reside on the Baja peninsula this winter only if steps are taken to bring back spiny cacti. This is supported by the claims that spiny cacti provide the only suitable nesting sites for this owl on the Baja peninsula, and that a recent blight destroyed all of the peninsula’s spiny cacti.

Notable Assumptions
The conclusion that taking steps to reestablish spiny cacti is necessary for the owls to reside on the Baja peninsula over the winter involves several assumptions:
- That spiny cacti will not reestablish themselves on the Baja peninsula before winter even if no steps are taken.
- That there are no other plants which could be introduced to substitute for spiny cacti.
- That suitable nesting sites are necessary for the owls to reside on the Baja peninsula over the winter.

A
No birds of prey other than the dwarf masked owl nest in the spiny cactus.
The impact of the cactus blight on other birds is irrelevant to this argument, which is purely about the impact on the dwarf masked owl.
B
If the Baja peninsula contains spiny cacti, then the dwarf masked owl makes its winter home there.
Posing spiny cacti as a sufficient condition for the owl to reside on the peninsula over winter doesn’t contribute to the conclusion that reestablishing cacti is a necessary condition. Like (D), this is unnecessary.
C
On occasion the dwarf masked owl has been known to make its winter home far from its normal migratory route.
Whether this owl has previously spent the winter elsewhere doesn’t affect whether reestablishing the spiny cactus is necessary for the owl to spend this winter on the peninsula.
D
The dwarf masked owl will not make its winter home on the Baja peninsula only if that region contains no spiny cacti.
Like (B), this makes spiny cacti a sufficient condition for the owl to spend winter on the peninsula. This isn’t necessary for the argument, which poses reestablishing the cacti as a necessary condition.
E
Suitable nesting sites must be present where the dwarf masked owl makes its winter home.
The argument concludes that reestablishing spiny cacti is necessary on the basis that they exclusively provide nesting sites for the owl. Without this assumption, that link of support would be broken and the conclusion would be unsupported.

22 comments

In the decade from the mid-1980s to the mid-1990s, large corporations were rocked by mergers, reengineering, and downsizing. These events significantly undermined employees’ job security. Surprisingly, however, employees’ perception of their own job security hardly changed over that period. Fifty-eight percent of employees surveyed in 1984 and 55 percent surveyed in 1994 stated that their own jobs were very secure.

"Surprising" Phenomenon
Why did corporate employees not perceive their job security to have changed appreciably from the beginning to the end of a decade during which their jobs were less secure?

Objective
The correct answer must fail to identify a reason for employees in 1994 to be as confident in their job security as employees in 1984. Every wrong answer, meanwhile, will provide a good hypothesis suggesting that the employees’ jobs were equally secure in both years, or that employees in 1994 were more likely than employees in 1984 to say their jobs were secure for a different reason.

A
A large number of the people in both surveys work in small companies that were not affected by mergers, reengineering, and downsizing.
This explains the consistent confidence measurement. The workers surveyed were largely not the ones at risk, so they did not perceive their job security to have changed much.
B
Employees who feel secure in their jobs tend to think that the jobs of others are secure.
This does not explain why employees remained apparently overconfident in their own job security. The author does not imply that employees were asked about other employees' jobs.
C
The corporate downsizing that took place during this period had been widely anticipated for several years before the mid-1980s.
This makes the consistent job confidence less surprising. If employees in 1984 were expecting downsizing, and employees in 1994 had experienced it, then employees in both years responded to the survey based on similar outlooks.
D
Most of the major downsizing during this period was completed within a year after the first survey.
This makes the consistent survey results less surprising. If the survey was conducted in years before and well after significant downsizing, employees in both years were likely not expecting it.
E
In the mid-1990s, people were generally more optimistic about their lives, even in the face of hardship, than they were a decade before.
This contributes to an explanation of the survey results. Employees in 1994 had an optimistic outlook that countered the effects of their declining job security to keep the survey results roughly consistent.

18 comments

Bardis: Extensive research shows that television advertisements affect the buying habits of consumers. Some people conclude from this that violent television imagery sometimes causes violent behavior. But the effectiveness of television advertisements could be a result of those televised images being specifically designed to alter buying habits, whereas television violence is not designed to cause violent behavior. Hence we can safely conclude that violent television imagery does not cause violence.

Summarize Argument: Counter-Position
Bardis concludes that television does not cause people to be violent. He supports this by drawing a distinction between shows with violent imagery and commercials, saying that commercials are intended to persuade people to buy a product whereas violent shows are not intended to persuade anyone to be violent.

Identify and Describe Flaw
Bardis’s reasoning is flawed because he only attempts to refute one point made by the opposing side without offering any actual support for his own conclusion. He challenges the claim that violence on TV is analogous to commercials, arguing that they’re not comparable. However, even if he’s successfully refuted that point, he still hasn’t actually answered the question: does violent imagery on TV lead to violence or not? There’s no support for his claim that it doesn’t.

A
relies on an illegitimate inference from the fact that advertisements can change behavior to the claim that advertisements can cause violent behavior
Bardis never claims that advertisements can cause violent behavior. His conclusion is that violent imagery on TV does not cause violent behavior.
B
fails to distinguish a type of behavior from a type of stimulus that may or may not affect behavior
Bardis does in fact distinguish between a type of behavior (violence) and a type of stimulus (violent imagery) since his conclusion is that televised violent imagery does not cause violence.
C
undermines its own position by questioning the persuasive power of television advertising
Bardis does not question the persuasive power of advertising. He acknowledges that commercials cause certain behaviors, but distinguishes those commercials from media with violent imagery.
D
concludes that a claim is false on the basis of one purported fault in an argument in favor of that claim
This describes how Bardis responds to an argument that compares commercials to violent media, but offers no support for his claim that there’s no causal relationship between violent imagery and violent behavior.
E
fails to consider the possibility that the argument it disputes is intended to address a separate issue
The argument addressed by Bardis claims that violent imagery sometimes causes violent behavior, so it’s concerned with the same issue. Regardless, the problem is that there’s no support for Bardis’s conclusion that violent imagery does not cause violence.

37 comments

Decentralization enables divisions of a large institution to function autonomously. This always permits more realistic planning and strongly encourages innovation, since the people responsible for decision making are directly involved in implementing the policies they design. Decentralization also permits the central administration to focus on institution-wide issues without being overwhelmed by the details of daily operations.

Summary
The stimulus says that decentralization allows different parts of a large institution to function autonomously. Autonomous functioning means that the same people are making decisions and implementing policies, which in turn allows more realistic planning and encourages innovation. Finally, decentralization lets the institution’s administrators focus on big-picture issues instead of daily operations.

Strongly Supported Conclusions
The stimulus supports these conclusions:
An institution whose divisions cannot function autonomously is not decentralized.
In institutions whose divisions do not function autonomously, planning is not always as realistic as possible.
If an institution’s central administrators are not able to focus on big-picture issues instead of daily operations, then the institution is not decentralized.

A
In large institutions whose divisions do not function autonomously, planning is not maximally realistic.
This is strongly supported. Based on the facts, when divisions function autonomously, planning becomes more realistic. That means that institutions without autonomous divisions could improve how realistically they plan—in other words, planning is not maximally realistic.
B
Innovation is not always encouraged in large centralized institutions.
This is not supported. Sure, decentralization encourages innovation, but that doesn’t mean that centralized institutions don’t encourage innovation. Maybe every type of institutional structure encourages innovation! We don’t know.
C
For large institutions the advantages of decentralization outweigh its disadvantages.
This is not supported. The stimulus discusses some advantages of decentralization, but we never learn about disadvantages at all. That means we can’t compare whether the advantages or disadvantages are more significant.
D
The central administrations of large institutions are usually partially responsible for most of the details of daily operations.
This is not supported. We know that decentralization allows administrators to not worry about daily operations, but that doesn’t tell us anything about how operations are usually managed. We don’t even know if most large institutions are decentralized or not!
E
The people directly involved in implementing policies are always able to make innovative and realistic policy decisions.
This is not supported. Based on the facts, this style of decision-making and implementation leads to more realistic planning and more innovation. But “more” is a comparison, not an absolute judgement. Even if planning gets more realistic, it might still be not very realistic.

59 comments

A television manufacturing plant has a total of 1,000 workers, though an average of 10 are absent on any given day for various reasons. On days when exactly 10 workers are absent, the plant produces televisions at its normal rate. Thus, it is reasonable to assume that the plant could fire 10 workers without any loss in production.

Summarize Argument
The author concludes that the manufacturing plant could fire 10 of its 1000 workers without any loss in production. Why? Because an average of 10 workers are usually absent anyway. And, when 10 workers are absent, production continues at the usual rate.

Identify and Describe Flaw
The author notes that 10 workers are usually absent on any given day. However, he fails to establish that it’s the same 10 people every day. Quite possibly, which workers are absent varies from day to day.
If so, firing 10 workers would decrease the manufacturing plant’s workforce. In addition to lacking the absentee workers, the plant would now lack the fired workers. And thus production might decrease.

A
ignores the possibility that if 10 workers were fired, each of the remaining workers would produce more televisions than previously
If the remaining workers produced more televisions, production would not go down—which would strengthen the author’s conclusion. So this can’t be the flaw.
B
fails to show that the absentee rate would drop if 10 workers were fired
The author’s conclusion requires the absentee rate to drop after the firings—but he doesn’t show that it would. Suppose the absentee rate stayed the same among the remaining workers. The workforce would then be missing both the absentee workers and the fired workers.
C
takes for granted that the normal rate of production can be attained only when no more than the average number of workers are absent
The author doesn’t presume that the normal rate of production can only be attained if the average number of workers or fewer are absent. He merely says that it is in fact attained when that number is absent.
D
overlooks the possibility that certain workers are crucial to the production of televisions
We have no specific reason to believe that the author overlooks this—unlike the flaw in (B).
E
takes for granted that the rate of production is not affected by the number of workers employed at the plant
This goes far beyond what the author is arguing: it would mean that even reducing the number of workers by 80% would not affect the rate of production! The author is only contending that the loss of 10 workers wouldn’t affect production.

42 comments