Source Map assignment (done in word doc below)

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Chapter 4 •

Learning Objectives

In this chapter you will learn to:

4.1 Explain the different kinds of evidence

4.2 Make your evidence persuasive by using the STAR criteria and other strategies

4.3 Understand evidence rhetorically by explaining how the selection and framing of evidence reveal an angle of vision

In Chapters 2 and 3 we introduced the concept of logos the logical structure of reasons and evidence in an argument and showed how an effective argument advances the writer's claim by linking its supporting reasons to one or more assumptions, beliefs, or values held by the intended audience. In this chapter, we turn to the uses of evidence in argument. By evidence, we mean all the verifi- able data and information a writer might use as support for an argument. In Toulmin's terms, evidence is part of the grounds or backing of an argument in support of reasons or warrants. By understanding evidence rhetorically, you will better understand how to use evidence ethically, responsibly, and persuasively in your own arguments.

Kinds of Evidence 4.1 Explain the different kinds of evidence.

You have numerous options for the kinds of evidence you can use in an argument, including personal experience, observations, interviews, questionnaires, field or laboratory research, or findings derived from researching primary or secondary sources found in libraries, databases, or the web. Carmen Tieu' s argument in Chapter 3 is based on personal experience. More commonly, college arguments require library and Internet research skills we teach in Part Two (Entering an

Using Evidence Effectively 53

Argumentative Conversation" ) and Part Five (" The Research ed Argument" ). This chapter focuses more basically on how evidence functions rhetorically in an argu- m ent and how it is selected and framed.

We be gin by cate gorizing and ev aluating different kinds of evidence, illustrating how each might be incorporated into an argument.

DATA FROM PERSONAL EXPERIENCE One powerful kind of evidence comes from p ersonal experience.

Example Strengths and Limitations

Despite recent criticism that Ritali n is overprescribed for hyperactivity and attention deficit d isorder, it can often seem li ke a miracle d rug . My little brother is a perfect example. Before he was given Ritalin, he was a terror in school . . .. [Tel l the "before" and "after" story of your litt le brother.]

• Personal-experience examples help readers identify w ith the writer; t hey show the writer's personal connection to the issue.

• Vivid stories capture the imagination and appeal to pathos . • Skeptics may sometimes argue that personal-experience

examples are insufficient (the writer is guilty of hasty generalization), not typical, or not adequately scientific or verifiable .

DATA FROM OBSERVATION OR FIELD RESEARCH You can also d evelop evi- d ence by p ersonally observing a phenomenon or by doing your own field research.

Example

The intersection at Fifth and Montgomery is particularly dangerous because pedestri- ans almost never find a comfortable break in the heavy flow of cars . On April 29, I watched fifty-seven pedestrians cross t he street. Not once d id cars driving in either direction on Fifth Avenue stop before the pedestrian stepped off the sidewalk to cross Montgomery Street. [Contin ue with observed data about danger.]

Strengths and Limitations

• Field research imparts a sense of scientific credibility. • Observations and field research increase typicality by

expanding the database beyond a si ngle example. • Observation and field research en hance the ethos of

the writer as personally invested and reasonable. • Skeptics may point to flaws in how observations

were cond ucted, showing how data are insufficient, inaccurate, or nontypical.

DATA FROM INTERVIEWS, QUESTIONNAIRES, AND SURVEYS You can also gather data by interviewing stakeholders in a controversy, creating ques- tionnaires, or conducting surveys. (See Chapter 16 for advice on how to conduct this kind of field research.)

Example

Another reason to ban laptops from class- rooms is the extent to which laptop users disturb other students. In a questionnaire that I d istributed to fifty students in my resi- dence hall, a surprising 60 percent said that they are an noyed by fellow students check- ing lnstagram, sendi ng e-mail, paying their bil ls , or surfing the Web while pretending to take notes in class. Add itionally, I inter- viewed five students w ho gave me specific examples of how these d istractions interfere w ith learning. [Report the examples.]

Strengths and Limitations

• Interviews, questionnaires, and surveys enhance the sufficiency and typicality of evidence by expanding the database beyond the experiences of one person.

• Quantitative data from questionnaires and surveys often increase t he argument's scientific feel.

• Surveys and questionnaires often uncover local or recent data not available in published research .

• Interviews can provide engaging personal stories, thus en hancing pathos .

• Skeptics can raise doubts about research method- ology, q uestionnaire design, or typicality of interview subjects.

54 Chapter 4

DATA FROM LIBRARY OR INTERNET RESEARCH For m an y arguments, evi- d ence is d erived from reading, particularly from library or Internet research. Part Five of this text helps you conduct effective research and incorporate research sources into your arguments.

Example

The belief that a high-carbohydrate, low-fat diet is the best way to lose weight has been challenged by research conducted by Walter Willett and his colleagues in the department of nutrition at the Harvard School of Public Health . Willett's research suggests that complex carbohydrates such as pasta and potatoes spike glucose levels, increasing the risk of diabetes. Add itionally, some fats- especially monounsaturated and polyun- saturated fats found in nuts, fish, and most vegetable oi Is- he I p lower "bad" cholesterol levels (45).*

Strengths and Limitations

• Researched evidence is often powerful , especially when sources speak with verifiable authority/ expertise on their subjects and are respected by your audience; writers can spotlight the source's credentials through attributive tags (see Chapter 17) .

• Researched data may take the form of facts, examples, quotations, summaries of research studies, and so forth .

• Skeptics might doubt the accuracy of facts , the cre- dentials of a source, or the research design of a study. They might also cite studies with different results.

• Skeptics might raise doubts about sufficiency, typicality, or relevance of your research data.

TESTIMONY Writers frequently u se testimony when direct data are either unavailable or highly technical or complex. Testimonial evidence can come from research or from interv iews.

Example

Althoug h the Swedish economist Bjorn Lomborg claims that acid rai n is not a sig- nificant problem , many environmentalists disagree. According to David Bellamany, president of the Conservation Founda- tion, "Acid rain does kill forests and people around the world, and it's still doing so in the most polluted places, such as Russia" (qtd . in BBC News) .

Strengths and Limitations

• By itself, testimony is generally less persuasive than direct data.

• Persuasiveness can be increased if the source has impressive credentials, which the writer can convey throug h attributive tags introducing the testi- mony (see Chapter 17).

• Skeptics might undermine testimon ial evidence by questioning the source's credentials, showing the source's bias, or quoting a countersource.

STATISTICAL DATA Many contemporary arguments rely h eavily on statistical data, often supplem ented by graphics such as tables, pie charts, and graphs. (See Chapter 9 for a discussion of the u se of graphics in argument.)

Example

After graduating from college, millennials aren't leaving their parents' homes the way college graduates used to. According to the U.S. Cen- sus Bureau's 2015 American Community Sur- vey, 34. 1 percent of people between the ages of eighteen and thirty-four lived in their par- ents' households, with the percentage even higher in states with high real-estate costs.

Strengths and Limitations

• Statistics can provide powerful snapshots of aggregate data from a wide database.

• Statistics are often used in conjunction with graphics. • Statistics can be calculated and displayed in differ-

ent ways to achieve different rhetorical effects, so the reader must be wary.

• Skeptics might question statistical methods, research design, and interpretation of data.

HYPOTHETICAL EXAMPLES, CASES, AND SCENARIOS Arguments occa- sionally use hypothetical examples, cases, or scenarios, particularly to illustrate conjectured consequences of an event or to test philosophical hypotheses.

*Parenthetical citations in this example and the next follow the MLA documentation system. See Chapter 18 for a full discussion of how to cite and document sources.

Example

Consider what might happen if we continue to use biotech soybeans that are resistant to herbicides. The resistant gene, through cross- pollination, might be transferred to an ordinary weed , creating an out-of-control superweed that herbicides couldn't kil l. Such a superweed cou ld be an ecological disaster.

Using Evidence Effectively 55

Strengths and Limitations

• Scenarios have strong imaginative appeal. • Scenarios are persuasive only if they seem plausible. • A scenario narrative often conveys a sense of

"inevitability" even if the actual scenario is unlikely; hence, the rhetorical effect may be illogical.

• Skeptics might show the implausibility of the scenario or offer an alternative scenario.

REASONED SEQUENCE OF IDEAS Sometimes arguments are supported with a reasoned sequence of ideas rather than with concrete facts or other forms of empirical evidence . The writer ' s goal is to support a point through a logical progression of ideas. Such arguments are conceptual, supported by linked ideas, rather than evidential. This kind of support occurs frequently in arguments and is often intermingled with evidential support.

Example

Embryonic stem cell research, despite its promise in fighting diseases, may have negative social consequences. This research encourages us to place embryos in the category of mere cellular matter that can be manipulated at will. Currently we reduce animals to th is category when we genetically alter them for human pur- poses, such as engineering pigs to grow more human-like heart valves for use in transplants. Using human embryos in the same way-as material that can be altered and destroyed at will- may benefit society materially, but this quest for greater knowledge and control involves a reclassifying of embryos that could potentially lead to a devaluing of human life.

Strengths and Limitations

• These sequences are often used in causal argu- ments to show how causes are linked to effects or in definitional or values arguments to show links among ideas.

• A sequence of ideas has great potential to clarify values and show the belief structure on wh ich a claim is founded.

• A sequence of ideas can sketch out ideas and connections that would otherwise remain latent.

• The effectiveness of this type of evidence depends on the audience's acceptance of each link in the sequence of ideas.

• Skeptics might raise objections at any link in the sequence, often by pointing to different val ues or outlining different conseq uences.

The Persuasive Use of Evidence 4.2 Make your evidence persuasive by using the STAR criteria

and other strategies.

We turn now from kinds of evidence to strategies for making evidence as convincing and p ersuasive as possible. Consider a target audience of educated, reasonable, and careful readers who approach an issue with healthy skepticism, open-minded but cautious. What d emands would such readers make on a writer's use of evidence? To answer that question, let's look at some general principles for using evidence persuasively.

Applyfhe STAR Criteria to Evidence Our open-minded but skeptical audience would expect the ev idence to meet what rhetorician Richard Fulkerson calls the STAR criteria:*

*Richard Fulkerson, Teaching the A rgumen t in W riting (Urbana, IL: National Council of Teach- ers of English , 1996), 44-53. In this section, w e are indebted to Fulkerson's discussion.

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Sufficiency: Is there enough evidence?

Typicality: Is the chosen evidence representative and typical?

Accuracy: Is the evidence accurate and up-to-date?

Relevance: Is the evidence relevant to the claim?

Let's examine each in turn.

SUFFICIENCY OF EVIDENCE How much evidence you need is a function of your rhetorical context. In a court trial, opposing attorneys often agree to waive evidence for points that aren't in doubt in order to concentrate on contested points. The more contested a claim or the more skeptical your audience, the more evidence you may need to present. On the one hand, if you provide too little evidence you may be accused of hasty generalization (see Appendix), a reason- ing fallacy in which you make a sweeping conclusion based on only one or two instances. On the other hand, if you provide too much evidence your argument may become overly long and tedious. You can guard against having too little or too much evidence by appropriately qualifying the claim your evidence supports.

Strong claim: Working full-time seriously harms a student's grade point average (much data needed probably a combination of examples and sta- tistical studies). Qualified claim: Working full-time often harms a student's grade point average (a few representative examples may be enough).

TYPICALITY OF EVIDENCE If readers are to trust your evidence, they need to be confident that you have chosen typical and representative cases rather than extreme or outlier cases. Suppose that you want to argue that students can suc- cessfully work full-time while going to college full-time. You cite the case of your friend Pam, who earned a straight-A grade point average while working forty hours per week as a night receptionist in a small hotel. Your audience might doubt the typicality of Pam's case because a night receptionist can often use work hours for studying. What about more typical jobs, they'll ask, where you can't study while you work?

ACCURACY OF EVIDENCE Evidence can't be used ethically unless it is accu- rate and up-to-date, and it can't be persuasive unless the audience believes in the credibility of the writer's sources. This criterion is particularly important in an era of "fake news" and "alternative facts." Arguers need to evaluate their sources, analyzing where each source might be placed on the continuum from "truth- seeking" to "persuasion" (see Figure 1.5). Ethical arguers must also develop an eye and ear for identifying reliable sources of data, distinguishing, for example, between widely respected news and public affairs sites and potential fake news sites. Later in this section, we illustrate our own fact-checking search to ensure the accuracy of a piece of evidence, explaining how we tracked down the original source for a piece of data cited in a The New Yorker article.

RELEVANCE OF EVIDENCE Finally, evidence will be persuasive only if the reader considers it relevant to what is at stake in the dispute. Consider the following student argument: "I deserve an A in this course because I worked exceptionally hard." The student then cites substantial evidence of how hard he worked a log of study hours, copies of multiple drafts of papers, testimony from friends, and so forth. But what is at stake here is the underlying assumption

Using Evidence Effectively 57

(warrant) that grades should be based on effort, not quality of work. The student provides ample evidence to support the reason ("I worked exceptionally hard"), but this evidence is irrelevant to the warrant ("People who work exceptionally hard deserve an A"). Although some instructors may give partial credit for effort, the criterion for grades is usually the quality of the student's performance, not the student's time spent studying.

Establish a Trustworthy Ethos Besides supplying evidence that meets the STAR criteria, you can make your evidence more persuasive by being fair, honest, and open to uncertainty (the appeal to ethos see Chapter 5). To establish your readers' confidence, you must first tell them the source of your evidence. If your evidence comes from personal experience or observation, your prose needs to make that clear. If your evidence comes from others (for example, through interviews or library /Internet research), you must indicate these sources through attributive tags (phrases like "according toT. Alvarez" or "as stated by a recent EPA report"). For academic papers, you must also cite and document your sources using an appropriate style for in-text citations and concluding bibliography. (Part Five of this text explains how to find, use, and cite research sources.) Finally, you need to be fair in the way you select evidence from your research sources. For example, it is unethical to take quota- tions out of context or to write an unfair summary that oversimplifies or distorts a source author's intended meaning.

Be Mindful of a Source's Distance froin Original Data When you support an argument through library /Internet research, you often encounter sources that report evidence from a second- or third-hand perspective. You need to imagine where your source author found the information that you now want to use in your own argument. How might you trace the process that led from the original data to your source author's use of it? Let's take as an example a passage from an article on the minimum wage by James Surowiecki writing for The New Yorker. (You can read the full article in Chapter 8.) Because the source is a magazine article rather than an academic paper, it contains no footnotes or bibliography, but the author nevertheless uses attributive tags to identify his main sources. Here is a passage from the article:

Passage from "The Pay Is Too Damn Low" by James Surowiecki

[O]ver the past three decades, the U.S. economy has done a poor job of cre- ating good middle-class jobs; five of the six fastest-growing job categories today; pay less than the median wage. That's why, as a recent study by the economists John Schmitt and Janelle Jones has shown,low-~ge workers are older and better educated than ever. More important, more of them are relying on their paychecks not for pin money or to pay for Friday-night dates but, rather, to support families.

Much of Surowiecki 's argument for increasing the minimum wage depends on evidence that low-wage workers are "older and better educated than ever." But we

Attributive tag (cites this study as his source)

Purported factual statement that we are

• • examining

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might ask: How does Surowiecki know about the age and education of low-wage workers? Why should we trust him? Using an attributive tag, he identifies his source as a recent study by economists John Schmitt and Janelle Jones. We conducted a Google search and quickly located the source: a working paper titled "Low-Wage Workers Are Older and Better Educated than Ever," dated April 2012. The paper was published by the Center for Economic and Policy Research, which, according to its Web site, is a nonprofit, nonpartisan research center aimed at providing factual economic data for public policy makers. So where did Schmitt and Jones get their data? They cite statistical tables compiled by the Current Population Survey, which is a joint effort of the Census Bureau and the Bureau of Labor Statistics. Based on these original data, Schmitt and Jones constructed two graphs showing shifts in the distribution of low-wage workers by age and then by education from 1971 to 2011. One of these graphs shows that in 1979, 26 percent of low-wage jobs were held by teenagers, but by 2011 only 12 percent of low-wage jobs were held by teenagers. (You can see this graph in Figure 8.3). In contrast, Schmitt and Jones's second graph shows that in 1979 only 25 percent of low-wage job holders had completed at least some college, but by 2011, 43 percent had completed some college.

Let's summarize the process we have just traced. The original data came from government statistics collected by the Census Bureau and the Bureau of Labor Statistics. Schmitt and Jones then converted these data into detailed graphs. Surowiecki then summarized the graphs' message into a single sentence. If you were to cite Surowiecki as your source of this same information ("low-wage work- ers are older and better educated than ever"), you would be depending on a chain of trust stretching from the original data through Schmitt and Jones and Surowiecki to you.

Of course, you can't be expected to trace all your research-gathered evidence back to the original data, but you need to imagine that it is possible to do so. The closer you can get to the original data, the more trustworthy your evidence. Unfor- tunately, fact-checkers employed by news sources or nonprofit organizations often discover that purportedly accurate information cannot be traced back to a credible original source. They might show that the information is not factual at all, that it is derived from flawed or discredited studies, that it has been distorted unfairly, or that it is purposely invented fake news in the service of propaganda. Politifact.com, a nationally respected fact-checker, uses a "truth-o-meter" to rank purported evidential statements along a scale from "True" to "False," with the most egre- giously false statements earning their famous "[Liar, Liar] Pants-on-Fire" award. To develop a respected ethos, you need to develop your own internal truth-o-meter by being aware of a source's distance from the original data and by occasionally tracing a piece of evidence back to its origins.

etorical Understanding of Evidence 4.3 Understand evidence rhetorically by explaining how the selection

and framing of evidence reveal an angle of vision.

In the previous section we presented some principles for persuasive use of evi- dence. We now ask you to look more closely at the rhetorical context in which evidence operates.

Angle of Vision and the Selection and Framing of Evidence

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When we enter the argumentative arena, we arrive as complex, whole persons, not as disembodied computers that reach claims through a value-free calculus. We enter with our own ideologies, beliefs, values, and guiding assumptions as formed by our particular lived lives. These differences help explain why one per- son's terrorist might be another person's freedom fighter, or why a handgun in a drawer might be one person's defense against intruders and another person's accident waiting to happen. In writing about guns, a believer in Second Amend- ment rights is apt to cite evidence that having a gun can stop a violent intruder or prevent a rape. Conversely, proponents of gun control are apt to cite evidence about accidental deaths or suicides. In an argument, evidence is always selected to further the arguer's claim and is never simply an inert, neutral"fact."

These guiding beliefs and values work together to create a writer's angle of vision: a perspective, bias, lens, filter, frame, or screen that helps determine what a writer sees or doesn't see. This angle of vision makes certain items stand out in a field of data while other items become invisible. The angle of vision both deter- mines and reveals the writer's view of which data are important and significant, and which data are trivial and can be ignored.

To help you better understand the concepts of selection and framing, we offer the following exercise based on different angles of vision regarding Uber, the ride- sharing company. Wildly popular in many cities, Uber has been accused of unfair or unsafe business practices causing dilemmas for city governments, regulatory agencies, insurance companies, and customers who want to avoid supporting socially irresponsible companies.

Suppose that your city has scheduled a public hearing on whether Uber needs stricter government regulations either for public safety or for ensuring fair busi- ness practices. The following pieces of data and evidence are available to the people who plan to attend the hearing.

• Uber has provided income opportunity for over 1 million drivers.

• Customers generally love Uber for the ease of its rider experience. The rider is automatically billed through the mobile app without the need to pull out a credit card or pay a tip.

• Some Uber drivers have complained of low pay and stressful work condi- tions. Uber data show that 11 percent of Uber drivers quit within a month, and about half quit within a year.

• Uber classifies its drivers as independent contractors rather than employees. Therefore, Uber doesn't have to provide health insurance, overtime pay, and other benefits.

• As independent contractors, Uber drivers have the freedom to work any hours they wish, and they accept only the riders and destinations they choose.

• In San Francisco, an Uber driver who was watching his Uber app for a poten- tial rider struck a six-year-old girl in a crosswalk. The parents sued Uber, but Uber lawyers claimed that the company bore no responsibility for the accident because the driver was an independent contractor and was not carrying a rider.

• Uber stores every user's ride-history data. If your Uber app is running, Uber can also track your location even if you aren't requesting an Uber

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ride. Uber has been accused of using its tracking data to dig up dirt on jour- nalists who are critical of Uber and to spy on Uber's rivals.

• Several independent studies have shown that a rollout of Uber in new areas is frequently associated with a decrease in drunk driving incidents.

• Several American cities have reported instances of Uber drivers sexually assaulting passengers. Two lawsuits in California accuse Uber of misleading customers about the quality of their background checks for drivers. As part of the suits, district attorneys cited findings that twenty-five Uber drivers in San Francisco and Los Angeles had criminal records.

• An Australian report found that Uber is less risky than a taxi because both passengers and drivers have profiles that can be checked before pickup. Unlike taxi services, Uber provides an online record of who the driver is.

• Taxicab drivers and union leaders complain that Uber's "surge pricing" poli- cies are unfair to both regulated taxi companies and to customers. During low demand times, Uber is cheaper than taxis; during surge times, customers are often surprised by a bill that is higher than what a taxi company would charge.

• One union leader for taxi drivers said: "Either the city should deregulate us [taxis] completely, like them [Uber] ... or regulate them at least closer to us, and let there be fair business competition."

For Writing and Discussion Creating Contrasting Angles of Vision

Individual task: Drawing on data that you select from the above list, compose two short speeches, one supporting the cur- rent Uber business model and one calling for more government regulat ion of Uber. Be ready to explain how you selected and framed data to create a pro-Uber angle of vision in one speech and an anti-Uber angle of vision in the other. How do data highlighted in one of your speeches become " less seen" or even "unseen" in the other?

Group task: Working in pairs or as a whole class, share your speeches with classmates. Then, after you have shared examples, explain the approaches that different classmates employed. What principle of selection was used? If arguers included evidence contrary to their positions, how did they handle it, respond to it, minimize its importance, or otherwise channel its rhetorical effect?

Examining Visual Arguments Angle of Vision Angle of vision can be conveyed visually as well as verba lly. The photos in Figures 4.1 and 4.2 display different angles of vision toward graffiti or street art, a controversial subject worldwide that affects urban dwellers' and tou rists' experience of public spaces. Suppose you are writ ing a short b lurb advertising city sights for a free t ravel magazine available at rental car agencies, hotels, and train stations. Which image

Using Evidence Effectively 61

Figure 4.1 Urban site with graffiti (Pearson Asset Library)

Figure 4.2 Urban site with graffiti (Source: June Johnson)

would you include w ith your magazine blurb? Why? Now suppose that you are blogging against graffiti and street art, perhaps urging city res idents to support tougher enforcement of laws against graffiti, which you see as vandalism. Which image would you choose? Why?

Analyze the features of the two photographs to explain how they are constructed to create alternative angles of vision on graffiti.

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Rhetorical Strategies for Framing Evidence What we hope you learned from the preceding exercises is that an arguer con- sciously selects evidence from a wide field of data and then frames these data through rhetorical strategies that emphasize some data, minimize other data, and guide the reader's response. Now that you have a basic idea of what it means to frame evidence, here are some strategies you can use to guide what the reader sees and feels.

STRATEGIES FOR FRAMING EVIDENCE

• Controlling the space given to supporting versus contrary evidence. Depending on your audience and purpose, you can devote most of your space to supporting evidence and minimal space to contrary evidence (or omit it entirely). Thus, people arguing in favor of Uber's current business model may have used the pro-Uber evidence from the list while omitting (or summarizing very briefly) the negative data about Uber.

• Emphasizing a detailed story versus presenting a lot of facts and statistics. Often, you can choose to support a point with a memorable individual case or with aggregate data such as statistics or lists of facts. A memorable story can have a strongly persuasive effect. For example, to argue for more government regulation of Uber, you might tell the harrowing story of the parents who sued Uber when a distracted Uber driver killed their daughter in a crosswalk. In contrast, a supporter of Uber might tell stories of happy Uber customers using the Uber app instead of standing on a corner trying to hail a taxi.

A different strategy is to use aggregate data such as facts and statistics rather than narratives. For example, a pro-regulation (anti-Uber) argument might use graphs to show how Uber has cut into the revenue stream of taxi companies, or it might use comparative data about the way different cities, states, or governments have tried to regulate ride-sharing companies like Uber and Lyft. In contrast, a pro-Uber argument might use data showing the cost savings of using uber rather than taxis.

Each method has its own strengths and weaknesses. The narrative story often has a powerful rhetorical effect, but it is always open to the charge that it is an insufficient or nonrepresentative example. Vivid anecdotes make for engaging reading, but by themselves they may not be compelling logically. In contrast, aggregate data, often used in scholarly publications, can provide more compelling, logical evidence but sometimes make the prose wonkish and dense.

• Providing contextual and interpretive comments when presenting data. When citing data, you can add brief contextual or interpretive comments that act as lenses over the readers' eyes to help them see the data from your perspec- tive. Suppose you want to support Uber, but you also want to admit that the Uber business model creates new problems. You could make these problems seem inconsequential with this sentence: "It is true that Uber has had occasional start-up problems, but that is to be expected whenever free enterprise creates a better business model." That sentence identifies Uber with creative free enter- prise while minimizing Uber's problems as "typical" of all start-ups. An Uber

Using Evidence Effectively 63

supporter might also spin Uber positively through an interpretive analogy that positions Uber as "modern" and taxis as obsolete: "Protecting taxi companies by regulating Uber is like protecting stagecoaches by regulating trains."

• Putting contrary evidence in subordinate positions. Just as a photogra- pher can emphasize or deemphasize an object by placing it in the center or the background of a photograph, you can place a piece of data in a subordinate or main clause of a sentence. Note how the structure of the following sentences changes the writer's angle of vision:

• "Although Uber drivers sometimes complain of stressful work conditions and low pay, they are free as independent contractors to work any hours they wish and accept only the riders and destinations they choose." (nega- tive data in subordinate clause deemphasizes it)

• "Although Uber drivers are free to work any times they wish and to accept only the rides and destinations they choose, drivers' complaints about low pay and high stress are frequent." (negative data in main clause empha- sizes it).

• Choosing labels and names that guide the reader's response to data. One of the most subtle ways to control your readers' response to data is to choose labels and names that prompt them to see the issue as you do. If you like Uber, you might call its business model"creative entrepreneurship," praising Uber for destroying the old, clunky regulations on taxis. In contrast, if you dislike Uber, you might call it a "dangerously unregulated predator" that steals fares from hardworking taxi drivers. The labels you choose, along with the connotations of the words you select, urge your reader to share your angle of vision.

• Using images (photographs, drawings, other graphics) to guide the reader's response to data. Another strategy for moving your audience toward your angle of vision is to include a photograph, drawing, or other graphic that portrays a contested issue from your perspective. Supporters of Uber might include an up-close photograph of an Uber app showing the location of the approaching driver. Anti-Uber images might depict taxi drivers participating in a protest demonstration. (See Chapter 9 for a complete discussion of using visuals in argument.)

• Revealing the value system that determines the writer's selection and fram- ing of data. Ultimately, how you select and frame evidence is linked to the system of values that organizes your argument. If you admire Uber, you prob- ably favor technological innovation and the "creative destruction" (of older business models) made possible by free markets. You might want government to require background checks for Uber drivers, but in general you likely want the government to stay out of the free market. If you don't admire Uber, you probably favor more government regulation aimed at ensuring consumer safety, enhancing workers' rights, and protecting consumers against fraud or false advertising. You may also have doubts about the sharing economy, which may benefit consumers but may have long-range negative effects on workers. If you are targeting an audience that shares your assumptions, you can frame your selected data by stating explicitly the values that guide your argument.

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Strategies for Framing Statistical Evidence Numbers and statistical data can be framed in so many ways that this category of evidence deserves a much closer look. By recognizing how writers frame numbers to support the story they want to tell, you will always be aware that other stories are also possible. Ethical use of numbers means that you use reputable sources for your basic data, that you don't invent or distort numbers to suit your own purposes, and that you don't ignore alternative points of view. Here are some of the choices you can make when framing statistical data:

• Numbers versus percentages. You can alter the rhetorical effect of a sta- tistic by choosing between numbers and percentages. If your uncle reports a $5,000 drop in his retirement account, that sounds scary. It sounds much less scary if he reports a 1 percent drop. You can apply this framing option directly to the Uber case. To emphasize the danger of sexual assault by an Uber driver, you can say that in a given year eight persons filed sexual assault suits against Uber. This use of numbers emphasizes each reported case. To minimize this statistic, you could report it as a percentage of the total number of Uber rides within the United States in a given year. When reported as a percentage, the sexual assault rate by Uber drivers is a tiny fraction of 1 percent.

• Median versus mean. Another way to alter the rhetorical effect of numbers is to choose between the median and the mean. The mean is the average of all numbers in a list. The median is the middle number when all the numbers are arranged in order from high to low. In 2016 the mean annual income of retirees aged 70-74 in the United States was $38,000 not a large amount of income, but enough to live on comfortably if the retirees owned their own home. However, retirees' median income in 2016 was only $23,000, a figure that points to a much more unequal income distribution among older Ameri- cans. This median figure means that half of the retired persons in this age bracket had annual incomes of $23,000 or less close to poverty level. The much higher mean income indicates that some retired Americans are very wealthy. This wealth raises the average of all incomes (the mean) but doesn't affect the median.

• Unadjusted versus adjusted numbers. Suppose your boss tells you that you are getting a 5 percent raise. You might be happy unless inflation rates are running at 6 percent. Economic data can be hard to interpret across time unless the dollar amounts are adjusted for inflation. This same problem occurs in other areas. For example, comparing grade point averages of college graduates in 1970 versus 2016 means little unless one can somehow adjust the numbers for grade inflation.

• Interval sizes on graphs. Whenever you draw a line graph, you can manip- ulate a curve's slope (angle) by the intervals you choose on the vertical axis. If you want to make a graph showing that Earth's average temperature has increased by 1.5 degrees Fahrenheit since 1850, the curve will look steep if you choose Y2 degree intervals on the vertical axis. However, if you choose five-degree intervals, the curve will look almost flat. You can see this dif- ference by comparing graphs produced by climate scientists (where global warming is made to "pop out") versus those produced by climate skeptics (where global warming is made to seem nonexistent). For more on graphic display of data, see Chapter 9.

Using Evidence Effectively 65

For Class Discussion Using Strategies to Frame Statistical Evidence A proposal to build a publicly funded sports stadium in a major American city y ielded a w ide range of statis- tical arguments. All of the following statements are reasonably faithful to the same facts:

• The stadium would be paid for by raising the sales tax from 8.2 percent to 8.3 percent for a twenty-year period.

• The sales tax increase is one-tenth of 1 percent. • The sales tax increase represents an average of $7.50 per person per year-about the price of a special

coffee drink and a pastry. • The sales tax increase represents $750 per f ive-person family over the twenty-year period in which

the higher tax is in effect. • For a famil y building a new home in this city, this tax will increase building costs by $200. • This is a $250 million tax increase for city res idents.

How wou ld you describe the costs of the proposed sports stadium if you opposed the proposal? How wou ld you describe the costs if you supported the proposal?

Creating a Plan for Gathering Evidence As you begin contemplating an argument, you can use the following checklist to help you think of p ossible sources for evidence.

A CHECKLIST FOR BRAINSTORMING SOURCES OF EVIDENCE

• What personal experiences have you had with this issue? What details from your life or the lives of your friends, acquaintances, or relatives might serve as examples or other kinds of evidence?

• What observational studies would be relevant to this issue?

• Which people could you interview to provide insights or expert knowledge on this issue?

• Which questions about your issue could be researched with a survey or questionnaire?

• What useful information on this issue might encyclopedias or specialized reference works in your university library provide?

• What evidence might you seek on this issue using licensed databases to search for relevant articles from magazines, newspapers, and scholarly journals?

• How might an Internet search help you research this issue?

• What evidence might you find on this issue from reliable statistical resources such as the U.S. Census Bureau, the Centers for Disease Control, or the website USA.gov? (For more information on the last four points, see Chapter 16.)

Conclusion Effective use of evidence is an essential skill for arguers. In this chapter we showed you various kinds of evidence ranging from personal experience to library I Internet research. We then discussed ways you can make your evidence persuasive

66 Chapter 4

by applying the STAR criteria, developing a trustworthy ethos, and being mindful of a secondary source's distance from the original data. We next examined how a writer's angle of vision influences his or her selection and framing of evidence. Finally, we described framing strategies for emphasizing, de-emphasizing, and guiding your reader's response to evidence.

Writing Assignment A Supporting-Reasons Argument Write an argument that uses at least two reasons to support your claim and appropriate evidence to develop your reasons. Your argument should include the features of a classical argument described at the beginning of Chapter 2 except that you can omit the section on summarizing and responding to opposing views, which we will cover in Chapter 6. This assignment builds on the brief writing assignments in Chapter 2 (create a thesis statement for an argument) and Chapter 3 (brainstorm support for one of your enthymemes using the Toulmin schema). Like a complete classical argument, a supporting-reasons argument has a thesis- governed structure in which you state your claim at the end of the introduction, begin body paragraphs with clearly stated reasons, and use effective transitions throughout to keep your reader on track. In developing your own argument, place your most important, persuasive, or interesting reason last, where it will have the greatest impact on your readers. A model for a supporting-reasons argument is Carmen Tieu's "Why Violent Video Games Are Good for Girls" in Chapter 3.