Evaluating Sources

We live in an information age, you may have heard people say. Indeed, typing “information age” into a popular search engine just now produced over 4 billion results in half a second! The problem is that much—perhaps most—of the information available, whether in print or online, is unsubstantiated, misleading, or downright false. How can we determine whether the information we search for is true?
In practice, we don’t usually verify particular facts. Instead, we focus on evaluating the credibility, or trustworthiness, of a fact’s source. I don’t know from personal experience or observation that Earth is one of eight planets in the solar system or that Abraham Lincoln delivered the Gettysburg Address on November 19, 1863. Instead, I accept these claims as true because I have learned them from sources I trust.

The better question, then, is how we may determine whether a source is credible. Unfortunately, there is no set of rules guaranteed to sort the good sources from the bad. Even the best sources—the most historically trusted and reliable—sometimes make mistakes or give incomplete accounts. Evaluating sources, then, should be a flexible process designed to help us do two main things:

  1. Identify untrustworthy sources and reject them.
  2. Identify promising sources and establish their credibility. 

The first goal can often be achieved quickly if we know how to spot red flags. The second goal must be pursued more methodically. In both cases, however, the process begins with asking questions. Here are some important questions to ask:

Who is the source’s author?

By “author,” I mean the person giving the information, whether through text, speech, film, or some other medium. The first step in evaluating a source is to identify the author and determine their qualifications: what authority or expertise supports their claims? If you cannot learn an author’s qualifications, you have no reason to trust them.

Qualifications do not have to be formal; someone who has lived in another country may know more about its culture than an academic who has never visited. However, they should be relevant to the specific topic being discussed. A professor of U.S. history is likely an authoritative source of information about democracy in the United States, but you should be more skeptical of claims they make about democracy in ancient Greece or communism in China.

You should also investigate whether an author has any biases or conflicts of interest that may hinder their ability to explain or describe something fairly. A politician sponsoring a bill may not be an objective source of information about that bill. A researcher who has been paid by a toothpaste manufacturer to study the benefits of a new brand of toothpaste may feel pressure to report positive results. Just as someone who lacks formal qualifications may still be a credible source, an apparent conflict of interest doesn’t necessarily prevent someone from giving accurate information. But it puts a greater onus on their audience to seek out additional information from less biased sources.

An example . . .

The importance of identifying and “vetting” a source’s author is a major reason why Wikipedia is not generally considered credible. Contrast Wikipedia’s article about World War II with Encyclopedia Britannica’s:

At the top of its article, Encyclopedia Britannica clearly identifies the two primary authors by name; each name links to a biography, revealing one author to be an academic with extensive relevant experience, and the other author to be an associate editor for the encyclopedia. (Encyclopedia Britannica has a long, trusted history as a credible publisher of information, and therefore—as the next section will emphasize—it is reasonable to trust its editors.)

In contrast, Wikipedia does not identify authors by name. Anyone can view the history of changes to an article (click on the “View history” tab, located at the top-right of the page), but these changes are attributed only to usernames; some usernames do provide a biography, but these biographies cannot be verified. (Encyclopedia Britannica also allows users to view an article’s history, but these changes are attributed to specific employees of the company.)

How has the information been published?

Usually the author of information is different from the person or organization that publishes it, but sometimes they are the same. Regardless, many of the questions to ask about a source’s author also apply to its publisher. Does the publisher have a longstanding reputation for integrity, for example, or a history of bias, egregious error, or propaganda? Generally, if you can establish a publisher’s credibility, you may assume the publisher has appropriately vetted its authors. Keep in mind, however, that credible publishers may produce a variety of content. A newspaper has sections for news as well as opinions, for example, and opinions are not usually expected to be authoritative or unbiased.

The question of how information has been published is particularly important when evaluating online sources. You can make some broad assumptions from

 a website’s domain extension: the brief (usually three letters) code that follows the “dot” in a URL. For example, .gov is used by government agencies and .edu by academic institutions. These sources are likelier to be credible than websites that end in .com, which typically belong to commercial companies or private individuals, or .org, which was initially intended for non-profit organizations but may in fact be used by anyone who pays the registration fee. Don’t take anything for granted, however. Many colleges and universities host personal web pages for their students—these pages also use the extension .edu, but they are less credible than pages created by faculty. And a commercial website may provide useful information about a company’s products or history.

Finally, it is worth considering a source’s overall appearance and design. While an attractive façade is no guarantee of quality, it can be a sign of professionalism and competence—just as typos and disorganization may signal the opposite. A publisher that consistently produces clear, clean content probably also has the resources to hold its authors to high standards and fact-check their claims.

How current is the information?

As a general rule, recent sources are preferable to older ones. This is especially true in the sciences, as new data make it necessary to revise or even reject theories that once were widely accepted. Historical accounts may also become fuller and more nuanced as time passes and people gain perspective and access to a wider range of sources. On the other hand, the latest “discoveries” aren’t necessarily true; if an old claim has never been disproved, its age may be strong evidence of its truth.

What evidence does the source present for a claim?

Of course, credible sources do more than note the lack of contradictory evidence for a claim—they actively provide evidence that the claim is true. Whatever form this evidence takes—quantitative data, personal observations, quotations from experts—it should be possible to evaluate its quality. Does the source explain how data were gathered, for example, and do these methods follow best practices? Are the personal observations, or the experts’ expertise, relevant to the claim? If not, why not? Was the author simply sloppy, or might their biases have led them to misuse or misinterpret evidence? You may have to do additional research to answer these questions—which bring us to one more:

Do other credible sources support the claim?

Information should not be examined in isolation. Especially if you are not yourself an expert, the best strategy for evaluating a given source, claim, or piece of evidence is to conduct research from a variety of credible sources. The more you learn about a topic, the better prepared you are to determine the general consensus regarding that topic. You can then consider any particular statement in the light of that consensus. If the statement is inconsistent with or contradicted by the consensus, but its author is otherwise credible, that may be an occasion for further research. Perhaps the author of an eccentric claim has discovered something new that forces you to reevalute your other sources. Or perhaps you can dismiss the claim—and even, by extension, the author.

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Ultimately, an effective process for evaluating sources must be adaptable. Different sources may require you to ask different questions and to follow up in different ways. You can do everything “right” and never be positive that a claim is true; contradictory information may surface years later. Often the most you can do, as a consumer of information, is consume from a variety of credible sources and trust the overlapping material to reveal the truth.

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