Writing Analytically, 6th Edition - Rosenwasser, David & Stephen, Jill.original_ [117]
We are, to a significant degree, a society obsessed with evidence—from UFO fanatics to conspiracy theorists to those who avidly follow the latest leaks in the press about the peccadilloes of the famous. This raises the question of the kinds of evidence that can be used to support claims.
MORE THAN JUST THE FACTS
As we have been suggesting for most of this chapter, evidence is virtually never simply a matter of “the facts.” It is no accident that one often hears the phrase “questions of evidence” because evidence is perennially subject to question—for its accuracy, its veracity, and so forth. When we hear that mellifluous voiceover in the TV commercial assuring us that “3 out of 4 dentists recommend a fluoride toothpaste,” how are we to take that remark? Why are lie detector tests “inadmissible as evidence” in some cases?
Nor is established practice a guarantee that the evidence is reliable. About 15 years ago, sportswriter Bill James levied a powerful attack on the accepted way of providing data for assessing a baseball player’s fielding—the fielding average, which was a ratio of the total number of balls hit to a fielder (his “chances”) as against his errors. James pointed out that fielding percentage didn’t take into account the greater number of balls that a superior fielder might get to in the first place, adding that the more difficult the chance, the more likely the player was to make an error. So the number of errors was not a reliable index of a player’s proficiency. Consequently, James invented a new statistical measure, the range factor, which more heavily weights the number of chances and devalues the number of errors. In effect, he redefines the pool of evidence.
What follows are some passages from student and professional writing, each of which illustrates a different kind of evidence. The list is not comprehensive, but we have tried to select a few of the most common categories.
STATISTICAL EVIDENCE
Statistics are a primary tool—a virtual language—for those writing in the natural and especially the social sciences. They have the advantage of greater objectivity, and, in the social sciences, of offering a broad view of a subject. Remember, though, that like other forms of evidence, statistics do not speak for themselves; their significance must be overtly elucidated. And, as the fielding average example suggests, it should never simply be assumed that statistics are valid representations of the reality they purport to measure.
The following brief excerpt is from a study of factors that determine Americans’ views on global warming, written by Christopher Borick and Barry Rabe (in Issues in Governance Studies, No.18, July, 2008).
Excerpt from “A Reason to Believe: Examining the Factors That Determine Americans’ Views on Global Warming”
Since the 1980s, there has been a growing body of data that examines the perceptions of Americans regarding the issue of global warming. This data paints a picture of generally increasing recognition, acceptance, and concern in the United States regarding atmospheric heating of the earth (Nisbet and Myers, 2007).
In the past two decades, the number of Americans who have heard of the “greenhouse effect” has steadily increased.
In 1986, less than one in four respondents said they had heard of global warming. By 2006, over nine out of ten recognized the issue (Nisbet and Myers, 2007). A growing number of Americans believe that the Earth is already experiencing increased heating as Table One shows. […]
Public opinion research shows Americans are increasingly acknowledging global warming (Nisbet and Myers, 2007); however, what isn’t seen are the underlying causes of these beliefs. In particular, what type of evidence do Americans cite