1705136272 D. Statistics are useful when a debater wants to make a generalization about some group of people or things. As in the case of argument by example, the debater does not have information about every individual in the group. A statistic starts with a description of a sample of the group, which allows the arguer to state that the sample probably is like the group as a whole. For instance, if 80% of the members of a debate team at a particular university are English majors, the inference could be drawn (rightly or wrongly) that 80% of all collegiate debaters are English majors. In some cases, a statistic can be a persuasive form of factual evidence. Statistics, used properly, are especially powerful evidence in the hands of a skilled debater.

1705136273

1705136274 Any form of evidence can be misleading, and statistics are no exception. Debaters need to be wary about statistics and examine them closely to make sure that the claim supported by the statistics is a good one. For instance, statistics show that women taking hormone replacement therapy have a lower-than-average incidence of coronary heart disease. One interpretation of this statistic is that hormone replacement therapy protects women against coronary heart disease.

1705136275

1705136276 However, a closer look at the data on which the statistic is based also shows that women who received hormone replacement theory were more likely to be from higher socio-economic groups with better-than-average diet and exercise regimens. Thus, the statistic supporting a relationship between hormone replacement therapy and coronary heart disease may be confounded by socioeconomic status of the women in the statistical sample (Lawlor, Smith, and Ebrahim 2004: 464-467). This is just one example where statistics can be misinterpreted. The main point is that statistics do not interpret themselves. People interpret statistics and need to be careful to provide accurate and complete interpretations.

1705136277

1705136278 E. Descriptions of empirical studies generally include statistics associated with a number of variables. Empirical studies are sometimes more persuasive than “raw statistics” because they are based on underlying theoretical explanations as well as on figures.

1705136279

1705136280 For instance, Shijie Yang collected statistics about the effect of hukou reforms on the income gap between rural and urban workers. Collecting data in five provinces between 1999 and 2005, Shijie Yang found that the hukou reforms in those provinces had the opposite of the intended effect. The study concluded that the hukou reforms “actually caused the income gap between urban and rural citizens to become wider, instead of narrower.”

1705136281

1705136282 That study gathered statistics about two variables: hukou reform, and the urban and rural income gap. The statistics were gathered systematically about each of the two variables and then were interpreted in a way that allows the researcher (and consumers of the research) to make a further statement about the relationship of the two variables. Well-conducted empirical studies are persuasive because of the systematic way evidence is gathered and interpreted. In the previous example, the authors began with an underlying theoretical position that hukou reforms would decrease the income gap. The authors then systematically gathered evidence related to both variables and finally interpreted the statistical evidence as inconsistent with the theoretical position with which the study began. In this particular case, the statistician began with theoretical position, and the data gathered actually cast doubt on the original position. Like statistics, different people can interpret empirical studies in different ways. Debaters need to take care to cautiously and accurately interpret empirical studies.

1705136283

1705136284 Thus, observed data, examples and illustrations, historical descriptions, statistics, and descriptions of empirical studies are included in the category called “facts.” Factual evidence of this kind, used well, can be quite persuasive in debate. Sometimes, a collection of facts is gathered together into a complex but coherent interpretation—a theory. The next category of evidence examines that idea of theory.

1705136285

1705136286 16.1.1.2 Theories Theories are used to explain or predict and, thus, can be used as evidence in various cases. In scientific circles, theories are more important than “mere” facts. These theories are formalized statements seeking to predict physical and social phenomena with greater or lesser precision depending on the theory. For instance, formal theories like Albert Einstein’s general and specific theories of relativity or Charles Darwin’s theory of evolution make predictions and explain phenomena.

1705136287

1705136288 But theories need not be that formal to be useful as evidence in argumentation and debate. For instance, debaters might use Samuel Peltzman’s theory of risk compensation to argue against the introduction of kinds of safety devices on automobiles. Peltzman’s theory, which grew out of a study in the mid-1970s about automobile regulation, has since become a much more general theory about risk compensation (Peltzman 1975: 677-726). In simple form, his theory asserts that, when governments issue safety regulations on things from automobiles to motorcycles to birth control devices, people who use those items engage in more risky behavior due to their perception that the safety concerns have been resolved.

1705136289

1705136290 Thus, the Peltzman theory could be used as evidence to argue against instituting more stringent seatbelt laws in China. The argument might go like this: Seatbelt laws will make drivers feel safer; that feeling of safety will cause drivers to drive more recklessly, thus endangering pedestrians and cyclists. The following diagram provides a visual illustration of such an argument:

1705136291

1705136292

1705136293

1705136294

1705136295 One of the reasons that theories are a persuasive category of evidence is that they offer apparently rational explanations for the relationships between and among facts. Contrary to popular opinion, facts do not speak for themselves. In the example presented above, someone might have noticed an increase in pedestrian deaths following the introduction of seatbelt laws, but might not be able to explain why the two phenomena were related. The theory provides just such an explanation. Furthermore, that explanation can then be generalized to other arenas that involve risk. So, a debater might use the theory to argue about related phenomena, such as sports helmets and speed limits.

1705136296

1705136297 Theories are important as evidence because they go beyond “mere” facts and provide seemingly sensible interpretations of the importance and meaning of the facts. Even explanations that are not formal theories are frequently necessary complements to factual evidence.

1705136298

1705136299 16.1.1.3 Presumptions Presumptions are a kind of evidence that does not necessarily describe reality, but describes how people expect reality to be. As such, presumptions are based on what people expect to happen in the ordinary course of events. Presumptions are based on facts, even though they are not facts themselves.

1705136300

1705136301 Presumptions can include assumptions about the nature of people in general, or about specific persons. They also can be about events expected to occur or not occur. For instance, we presume that, next winter, the weather in Guangxi will be warmer than the weather in Harbin. That presumption is not an observable fact because we cannot observe next winter’s weather today. However, the weather in Guangxi has been warmer for so many winters that we presume it will, again, be warmer next winter. We can use that presumption as evidence for a number of arguments, such as, where the family might vacation next December.

1705136302

1705136303 Sometimes, we make presumptions about a particular person based on our previous knowledge of that person or that person’s family characteristics. For instance, someone might argue that Wang Jingkai will become a public servant in China because many of his family members have done so. In this case, the presumption that a particular person will go into public service is based on a fact that other members of his family did just that.

1705136304

1705136305 The laws of many nations contain a concept called a “rebuttable presumption.” Those presumptions are “rebuttable” because a legal system has declared that the presumption stands until other evidence overcomes it. In the area of adoption law, for example, a rebuttable presumption is used to presume that, if a woman is married when she gives birth to a child, her husband is the father. Thus, when one sees a child accompanied by a married woman and her husband, that person might presume that the wife is the mother and the husband is the father. Although one can think of numerous reasons why the presumption might be incorrect, it is a presumption, nevertheless.

1705136306

1705136307 思辨精英：英语辩论-构筑全球视角 [:1705132481]

1705136308 16.1.2 Evidence Based on Preference

1705136309

1705136310 Because presumptions are frequently as much about how things “ought” to be as about how they really are, presumptions blur the distinction between evidence pertaining to reality and evidence pertaining to preference. The next three categories, however, provide examples of evidence that falls squarely in the category of evidence pertaining to preference.

1705136311

1705136312 16.1.2.1 Value Values provide evaluations of objects, persons, ideas, institutions, etc. Any statement expressing something other than indifference about an object7 is a statement of value. By their nature, values are abstract, but can become more concrete when connected to an object to be evaluated. To argue that Ge is pretty or Jinkai is handsome is to attach a value of beauty to a human object. Although evidence is ordinarily thought of as factual, values also serve as evidence in argument.

1705136313

1705136314 One clear example of how a debater can use value as evidence occurs in arguments about the American system of health care. America is currently involved in an argument over whether it should provide universal health care to all citizens. Those who favor universal health care believe that the right to health care is an important value. Therefore, the value of the right to health care might be used as evidence to support the claim American should adopt a system of universal medical care for all its citizens. Because we do not ordinarily think of values as evidence in argumentation, perhaps a diagram of such an argument may help explain that category:

1705136315

1705136316

1705136317

1705136318

1705136319 The example in the previous diagram shows how a value can be combined with a fact to provide evidence to support a claim. In that case, the value involves the right to health care, and the fact is a statistic involving the number of Americans who do not have access to health care. Both of the two pieces of evidence are then combined to support a claim that “America should adopt a system of universal health care.” This example demonstrates that values can be important sources of evidence, especially in claims of evaluation.

1705136320

1705136321 One problem in using values as evidence is that sometimes audiences hold competing values related to a particular object. With regard to the previous illustration of universal health care, some might also maintain the value of the necessity of reducing the cost of government. While the right to health care might be used to argue for the claim that America should provide a system of universal health care, the value of reducing the cost of government might mitigate against that claim. In situations where values such as the right to health care and the cost of government collide, the more important type of evidence concerns value hierarchies.

[ 上一页 ]  [ :1.705136272e+09 ]  [ 下一页 ]