Statistics—numerical data about a given population sample—are often used to support position arguments because readers tend to find statistical evidence especially convincing. Numbers can seem impressive—as, for example, when Jessica Statsky refers to the research finding that about 90 percent of children would choose to play regularly on a losing team rather than sit on the bench of a winning team (par. 5). Readers are likely to accept such a high percentage at face value because they would probably share the preference for playing over watching. However, without knowing the size of the sample (90 percent of 10 people, 100 people, or 10,000 people?), it is impossible to judge the significance of the statistic. Moreover, without knowing who the researchers are and how their research was funded and conducted, it is also difficult to judge the credibility of the statistic. That’s why most critical readers want to know the source of statistics to see whether the research is peer-reviewed—that is, whether it has been evaluated by other researchers knowledgeable about the subject and able to judge the reliability of its findings.