I've been preparing GRE writing by myself for a long time, with little improvement. I badly need your advices. Please review my writing below and give me feedbacks. Thank you!
The following appeared in a heart magazine published in Corpora.
"Medical experts say that only one-quarter of Corpora's citizens meet the current standards for adequate physical fitness, even though twenty years ago, one half of all of Corpora's citizens met the standards as then defined. 2. But these experts are mistaken when they suggest that spending too much time using computers has caused a decline in fitness. 3 Since overall fitness levels are highest in regions of Corpora where levels of computer ownership are also highest, it is clear that using computers has not made citizens less physically fit.4. Instead, as shown by this year's unusually low expenditures on fitness-related products and services, the recent decline in the economy is most likely the cause, 5 and fitness levels will improve when the economy does."
Write a response in which you examine the stated and/or unstated assumptions of the argument. Be sure to explain how the argument depends on these assumptions and what the implications are for the argument if the assumptions prove unwarranted.
This is a fairly weak argument. While denying that people's spending too much time using computers in Corpora as a cause to the physical fitness decline, the author tries to prove that the real cause is the recent decline in the economy. However, the argument is suffered with a number of questionable assumptions, which make the argument much less convincing.
First of all, the author points out there is a decline in physical fitness among citizens in Corpora, by citing what the medical experts have said. There are two main problems in the experts' statement, namely, assuming the population in Corpora is the same as 20 years ago and the physical standards used this time are the same as 20 years' ago. Because neither the author nor the experts point out whether the population has been more or less the same during these 20 years, we can't be sure of this. There might be much more people now in Corpora, and many of them are senior citizens. Because of their ages, they might be not as healthy and strong as young people. In contrast, the percent of young people in Corpora might be much higher than now. As a result, it is only natural there are less people meeting the physical fitness standards. If this happens to be true, the decline in the economy would not be the main cause of the decline of physical fitness levels.
Besides the population change, the physical standards could have changed too. It seems the author believes that the standards are the same, otherwise the statistics then and now can not be compared. But the author doesn't say that. Suppose the standards used this time is much higher than that of 20 years ago, people should be surprised the percentage of fit people has dropped from one half to one quarter. Furthermore, are the survey done by the same medical experts? If not, are the using in the same methodologies in the survey. If either of these two factors are different, people will need to check if it has an influence on the results. Different standards, different people conducting the survey or different methodologies could have made fit percentage decline. In turn, the arguments conclusion will be proved not reliable.
Believing there really is a decline in peoples' fitness in Corpora, the author assumes the lower expenditures on fitness products and services mean there are less people doing exercise. However, exercise with fitness products and going to the gym are not the only ways of getting fit. Citizens can also go to parks jogging, which almost will cost nothing but gas and water. If this is true, the decline in the economy would not be the main cause either.
The author also assumes that there are only two things could cause the fitness decline, namely people's spending too much time on computers and decline in the economy. Since he or she has prove the first reason false, she assumes the second one must be the right answer. In fact, there might be many other alternative explanations.
As what has been stated before, population differences, survey method differences and different standards could be the explanations as well. Therefore, it might not be the economy making the change.
By stating the economy is the real cause, the author also assumes that the economy 20 years ago is better than now. If it is true, the author should better tell us. If it's not, it will undermine her argument.
In conclusion, the argument has left too many questions unanswered and too many assumption unproved. To make it believable, the author would need to provide more statistics concerning the standards used, the demographic statics in Corpora and the economy backgrounds.