Rules for writers, Tenth edition - Diana Hacker, Nancy Sommers 2021
Evaluate the evidence behind an argument
Reading arguments
Academic Reading and Writing
Writers draw on facts, statistics, examples, expert opinion, and appeals to support their arguments. As you read an argument, look closely at the evidence behind the argument. Ask the following questions:
✵ Is the evidence accurate and fair?
✵ Is the evidence sufficient?
✵ Is the evidence representative?
✵ Is the evidence relevant?
As you read, take time to reflect on the author’s use of evidence. Pose counterarguments to test the strength of the author’s argument and to consider alternative interpretations of the evidence. Try using these sentence starters to analyze the evidence and the author’s argument:
✵ X’s evidence is relevant/no longer relevant because .
✵ X’s evidence is biased and/or insufficient because .
✵ Looking at X’s evidence, couldn’t we also conclude that ?
✵ X argues , but what she hasn’t taken into interpretation is .
✵ X’s argument rests on this faulty assumption: .
QUESTIONING THE EVIDENCE BEHIND A CONCLUSION
When authors construct an argument, they often use inductive reasoning — drawing a conclusion based on a piece of evidence. You can test the evidence and the conclusion an author has made with the following questions.
CONCLUSION |
The majority of students on our campus would volunteer at least five hours a week in a community organization if the school provided a placement service for volunteers. |
EVIDENCE |
In a recent survey, 723 of 1,215 students questioned said they would volunteer at least five hours a week in a community organization if the school provided a placement service for volunteers. |
1. Is the evidence accurate and fair? The evidence is trustworthy if the survey was conducted fairly and objectively. In weighing the accuracy of survey evidence, ask questions about who conducted the survey and the methods used to collect and analyze data.
2. Is the evidence sufficient? That depends. On a small campus (say, 3,000 students), the pool of students surveyed would be sufficient for research, but on a large campus (say, 30,000 students), 1,215 students would be only 4 percent of the population. If those 4 percent were known to be truly representative of the other 96 percent, however, even such a small sample would be sufficient (see question 3).
3. Is the evidence representative? The evidence is representative if those responding to the survey reflect the entire student population with respect to the characteristics of age, gender, race, field of study, number of extracurricular commitments, and so on. If most of those surveyed are majors in a field such as social work, question the survey’s conclusion.
4. Is the evidence relevant? Yes. The survey results are directly linked to the conclusion. A survey about the number of hours students work for pay, by contrast, would not be relevant because it would not be about choosing to volunteer.