Argument 33
A new study collected data that shows that people who snore are more likely to gain weight
than are people who do not snore. It is well known that many people who snore also stop
breathing frequently during the night for a few seconds, a condition called sleep apnea. The
interruption of breathing wakes the person---often so briefly that the waking goes
unnoticed---and can leave the person too tired during the day to exercise. Anyone who snores,
therefore, should try to eat less than the average person and to exercise more
In this argument the speaker concludes that any person who snores should try to eat less
and exercise more than the average person. To justify this conclusion the speaker points out
that many snorers awaken frequently during sleep--often so briefly that they are unaware that
they are awake in order to catch their breath (a condition called sleep apnea), and as a result
are too fired during normal waking hours to exercise. The speaker also cites data collected
during a recent study, suggesting that snorers are more likely to gain weight than other people.
This argument is flawed in several critical respects.
First, the speaker provides no assurances that the recently collected data suggesting a
correlation between snoring and weight gain are statistically reliable. Perhaps the study’s
subjects were unrepresentative of the overall population in terms of other traits and habits
that might affect body weight. Lacking such evidence the speaker simply cannot draw any firm
conclusions based on the study about the relationship between snoring and weight gain.
Even assuming a strong correlation between snoring and weight gain among the general
population, the speaker has not adequately shown that sleep apnea causes weight gain. A
correlation is one indication of a causal relationship, but in itself does not suffice to prove such
a relationship. It is entirely possible that some other medical condition, or some other trait or
habit, that causes snoring also causes weight gain. Without establishing dearly that snoring at
least contributes to weight gain, the speaker cannot convince me that snorers should either eat
less or exercise more than the average person.
Even ifmany snorers suffer from sleep apnea and tend to gain weight as a result, the
speaker’s advice that "anyone who snores" should try to eat less and to exercise is new
ertheless unwarranted. It is entirely possible that some--or perhaps even most--snorers do not
suffer from sleep apnea, or are not too tired to exercise, or do not in any event tend to gain
weight. Without ruling out these possibilities, the speaker must expressly limit the advice to
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those snorers whose snoring causes weight-gain.Even if the speaker’s advice were modified as indicated above, the advice to exercise would
still be logically unsound. If a person with sleep apnea is too tired to exercise as a result, then
simply advising that person to exercise begs the question: What should the person do to
eliminate the cause of the tiredness? Thus the speaker should determine the cause of sleep
apnea and modify the advice so that it targets that cause. Of course, ifit turns out that weight
gain is one cause of snoring and sleep apnea, then the speaker’s advice that snorers should
try to eat less would have considerable merit. Yet, without any evidence that this is the case,
the speaker’s advice might be at least partially ineffective in counteracting a snorer’s tendency
to gain weight.
In sum, the speaker’s advice for "any" snorer is ill-conceived and poorly supported. To lend
credibility to this advice the speaker should provide evidence that the recently collected data
reflect the general population. To better assess the argument it would be useful to know all the
possible causes of snoring and of sleep apnea.
Argument 34
The following appeared in the editorial section of a local newspaper.
"The librarians in our town’s school system have reported that the number of trips that our
students make to their school library on a voluntary basis has decreased significantly in recent
years. For example, the average seventh-grade student visited the school library five times
last year, but four of those visits were part of required classroom activities. This shows that our
students are reading less than in the past. To address this problem, our town needs to improve
the atmosphere of the libraries so that they will be comfortable places in which to work. If
students view the libraries as uncomfortable, then they are unlikely to want to spend much time
there."
In this editorial the author claims that the town’s students are reading less, and that by
improving the atmosphere in the town’s school libraries students would visit their school library
more frequently and, in turn, would read more. To support these claims the author points out
that the number of annual visits students make to their school library, on average, has
decreased significantly in recent years. Specifically, the average seventh grader paid five such
visits last year, four of which were required for classes. Close inspection of the evidence
reveals, however, that it lends little credible support for the proposed course of action.
First, the author unfairly assumes that since the number of library visits per student is
declining the amount of reading on the part of students must also be declining. This poor
assumption overlooks the possibility that students are doing more reading or checking out
more reading materials during each library visit. It also ignores the possibility that more and
more students are obtaining reading material elsewhere--for example, from public libraries or
from the Internet. Without considering and ruling out these possibilities, the author cannot
justifiably conclude that students are reading less merely because they are visiting their school
library less often.Secondly, the author assumes that the reason for the declining number of library visits is that
the library is uncomfortable. Yet, the author offers no evidence to substantiate this assumption.
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Lacking such evidence, a variety of other factors might account for the decline. As noted above,
perhaps students are becoming less dependent on the school library for obtaining reading
material and information. Besides, lacking evidence to the contrary it is entirely possible that
library atmosphere is completely insignificant to most students.
Thirdly, the author assumes that improving atmosphere and comfort is necessary to reverse
the current trend. However, even if the surroundings go unchanged there might be other ways
to attract students to their library. Perhaps increasing the number of computer terminals or the
number of staff members would reverse the current trend. Or perhaps increasing the number
of books and periodicals, or enhancing their variety, would be effective. In short, without ruling
out all other possible means of achieving the desired results, the author cannot convince me
that the proposed course of action is necessary.
Finally, the author assumes that improving the library’s atmosphere would suffice to increase
the frequency of student visits and the amount of reading on the part of students. Yet, the
author offers no evidence that these improvements alone would suffice. In fact, a more
comfortable library might actually discourage students from reading by creating a social rather
than work atmosphere.
In sum, the recommendation is not well supported. To strengthen the argument the author
must provide clear evidence that the school’s students are in fact reading less and that if they
visit the school library more frequently they will read more. The author must also provide
evidence--perhaps by way of a student survey--that the library atmosphere is the chief
determinant of the frequency with which students visit the library. Finally, to better evaluate the
argument I would need to know what alternatives, if any, are available for increasing the
frequency with which students visit their library, and for increasing the amount that students
read.
Argument 35
The following appeared in an editorial in a business magazine.
"Although the sales of Whirlwind video games have declined over the past two years, a recent
survey of video-game players suggests that this sales trend is about to be reversed. The
survey asked video-game players what features they thought were most important in a video
game. According to the survey, players prefer games that provide lifelike graphics, which
require the most up-to-date computers. Whirlwind has just introduced several such games with
an extensive advertising campaign directed at people 10 to 25 years old, the age-group most
likely to play video games. It follows, then, that the sales of Whirlwind video games are likely to
increase dramatically in the next few months."