In the video, I showed one way in which a small increase in average could have resulted in a large increase in the proportion of obese children. There are other ways too.

Here's one of those ways. Even if everyone gained exactly one pound, it may be the case that there were so many previously-almost-obese-children (within 1lb of obesity) or so few previously-obese children that the one pound gain increases the obese proportion dramatically.

Here's another. A lot of kids could have lost weight. To compensate for those kids losing weight, we'd have to have a lot of kids gaining weight to increase the total average by 1lb. Those kids that gain weight could be the large increase in obese children. If you're statistically inclined, think of it this way. Assume weight is normally distributed. Flatten the curve in the middle and shift the entire curve 1lb to the right. You would get substantially more obese children with a substantial flattening of the curve.


7 comments

In the video, I showed one way in which a small increase in average could have resulted in a large increase in the proportion of obese children. There are other ways too.

Here's one of those ways. Even if everyone gained exactly one pound, it may be the case that there were so many previously-almost-obese-children (within 1lb of obesity) or so few previously-obese children that the one pound gain increases the obese proportion dramatically.

Here's another. A lot of kids could have lost weight. To compensate for those kids losing weight, we'd have to have a lot of kids gaining weight to increase the total average by 1lb. Those kids that gain weight could be the large increase in obese children. If you're statistically inclined, think of it this way. Assume weight is normally distributed. Flatten the curve in the middle and shift the entire curve 1lb to the right. You would get substantially more obese children with a substantial flattening of the curve.


7 comments

Warner: Until recently, most competitive swimmers were high school or university students. Now, more and more competitive swimmers are continuing well beyond their university years. Clearly, better training regimens have allowed today’s competitive swimmers to stay fitter longer than swimmers of the past.

Young: Not necessarily. No one has the time to both be a competitive swimmer and hold an outside job. But unlike in the past, today’s competitive swimmers can make a living at their sport.

Summarize Argument: Counter-Position
Warner hypothesizes that better training regimens are the explanation for why more and more competitive swimmers are continuing to compete long beyond their university years.
Young proposes a different hypothesis for the increased longetivity of competitive swimming careers. Before, swimmers couldn’t make a living at their sport, so had to quit to get a job. But now, swimmers can make a living at their sport.

Describe Method of Reasoning
Young proposes an alternative explanation for the longetivity of competitive swimming careers.

A
attempting to demonstrate that the evidence Warner advances actually undermines Warner’s conclusion
Warner’s evidence doesn’t undermine his own conclusion. Young simply presents a different explanation that Warner doesn’t consider.
B
presenting a counterexample in order to weaken the evidence offered in support of Warner’s conclusion
Warner doesn’t actually offer any evidence in favor of his hypothesis. In addition, Young doesn’t present an example of competitive swimmers who don’t have better training regimens or whose better training regimens don’t allow them to stay fitter for a longer time.
C
arguing that a condition that Warner takes to be sufficient to account for a phenomenon is necessary but not sufficient
Young doesn’t claim that anything is necessary in order to explain the increased longevitiy of competitive swimmers. He simply presents a different hypothesis.
D
maintaining that the evidence presented in support of Warner’s conclusion presupposes the truth of that conclusion
Young doesn’t accuse warner of using circular reasoning (where the conclusion assumes the truth of the premise).
E
offering an alternative to Warner’s explanation of a certain phenomenon
Young offers an alternative explanation for the increased longevity of competitive swimmers. Rather than being a result of better training, it might be due to more swimmers being able to make a living as a swimmer nowadays.

3 comments

Consumer: A new law requires all cigarette packaging to display health warnings, disturbing pictures of smoking-related diseases, and no logos. This law will not affect the smoking habits of most people who smoke cigarettes regularly, since most of these people rarely look at the packaging when they take out a cigarette.

Summary
The author concludes that the new law concerning cigarette packaging will not affect the smoking habits of most people who smoke cigarettes regularly. Why? Because most of these people rarely look at the packaging when they take out a cigarette.

Missing Connection
We’re trying to conclude that the new law won’t affect most regular smokers’ smoking habits. But the premise doesn’t tell us what allows us to know when a law will have no effect on regular smokers’ habits. All that the premise establishes is that most regular smokers rarely look at cigarette packaging when taking out a cigarette. But does failing to look at cigarette packaging when taking out a cigarette imply that the packaging can’t be effective in deterring people from smoking? Not necessarily.
To make the argument valid, then, we want to establish that if regular smokers rarely look at cig. packaging when taking out a cig., then the packaging won’t affect their smoking habits.

A
If implementing certain regulations on the packaging of cigarettes would affect the smoking habits of those who smoke cigarettes regularly, those regulations should be implemented.
We’re trying to prove that the regulations on packaging won’t affect regular smokers’ habits. Whether the regulations should be implemented is a separate, irrelevant issue.
B
If those who regularly smoke cigarettes look at disturbing pictures of smoking-related diseases frequently, it is likely to affect their smoking habits.
(B) is designed to reach a conclusion that something is likely to affect smoking habits; but we want to prove that something will NOT affect smoking habits.
C
Almost all people who regularly smoke cigarettes are already familiar with the risks that smoking poses to their health.
Even if most regular smokers are already familiar with the risks of smoking, that doesn’t guarantee that packaging warnings won’t affect their smoking habits. Perhaps the packaging could encourage them to smoke less often. So (C) doesn’t guarantee that the new packaging won’t affect smoking habits.
D
The new packaging cannot affect the smoking habits of people who regularly smoke cigarettes unless they frequently look at the packaging when taking out cigarettes.
(D) establishes that in order for the new packaging to affect smoking habits of someone, that person must frequently look at the packaging when taking out cigs. We know that most regular smokers don’t frequently look at the packaging when taking out cigs. According to (D), then, the new packaging cannot affect the smoking habits of those people.
E
Most people who regularly smoke cigarettes would be unable to describe the logo of their usual brand of cigarettes if asked to do so.
(E) doesn’t establish anything about what’s required for packaging to affect smoking habits. Remember, we already know that most regular smokers don’t frequently look at cig. packaging when taking out cigs. What we want is to connect that fact to lack of effectiveness in changing smoking habits.

3 comments

Edgar: Nurses who have been specially trained in administering anesthetics should be allowed to anesthetize patients without having to do so under a doctor’s supervision. After all, anesthesia has gotten remarkably safe in recent decades.

Janet: Although it’s true that nurse anesthetists receive excellent training, only doctors have the broader medical training to handle the rare emergencies that can arise.

Speaker 1 Summary
Nurses trained in administering anesthetics should be allowed to anesthetize patients without doctor supervision. Why? Because anesthesia has gotten remarkably safe in recent decades.

Speaker 2 Summary
Even though nurse anesthetists receive excellent training, only doctors have the broader training to handle rare emergencies that can arise.

Objective
We need a statement that Edgar and Janet disagree on. They disagree whether nurse anesthetists should have doctor supervision. Edgar disagrees because anesthesia has gotten safer. Janet agrees because only doctors have the necessary training to handle rare emergencies.

A
nurses should ever be allowed to anesthetize patients
Both speakers agree with this statement. Edgar thinks that nurses should be able to anesthetize patients without doctor supervision. Janet thinks that nurses should be able to anesthetize patients with doctor supervision.
B
emergencies that can develop from anesthesia are rare
Edgar does not express an opinion on this statement. Edgar thinks that anesthesia has gotten safer, but this is not necessarily equivalent to expressing that emergencies are rare.
C
nurses should be given more training in administering anesthetics
Neither speaker expresses an opinion on this statement. In fact, the speakers may disagree, since both acknowledge that nurse anesthetists are specially trained.
D
the safety of anesthesia has improved in recent decades
Janet does not express an opinion on this statement. Janet only expresses that only doctors are capable of handling rare emergencies.
E
the administration of anesthetics by a nurse should always be supervised by a doctor
Edgar and Janet disagree on this statement. Edgar disagrees and thinks nurse anesthetists should be able to anesthetize patients without doctor supervision. Janet agrees because only doctors are capable of handling a rare emergency.

2 comments