Is it current? If you’re writing about college dorm policies in the 2000s, an essay written in 1940 won’t help. If you’re writing about noninvasive kidney surgery, anything written before 2003 probably lacks insight on the latest procedures.

Publication dates of quality sources are easily identifiable, and as a general rule, you want to look at the most recent articles available. These are often journal articles.

Web sites are extremely current. Trustworthy web sites will regularly update information and clearly indicate the information’s date, the date it was published on the web, and any revision dates. If this information isn’t available, the web site is less reliable than it could be.

Is it relevant? All information should support your thesis and assertions. If you were to evaluate women’s fashions of the 1920s, your professor would expect you to read publications from that decade as well as recent articles evaluating that era. In this case, the relevancy of the older material is as high as (or higher than) the contemporary analysis. Additionally, your professor would not expect you to read essays about transparent lederhosen in the 1980s.

Is it biased? Because you read Nietzsche in your free time, you know every writer has an intention—even if s/he claims to be completely, 100 percent neutral and intention-free. No person is completely objective. At the very least, a person will be favorable towards her/his own views (otherwise s/he would probably not hold them). Because of this, some degree of bias must be accepted, provided that the bias is not significant. What counts as a significant degree of bias is open to dispute and can vary a great deal from case to case. For example, many people would probably suspect that doctors paid by tobacco companies to research the effects of smoking would be biased. Are doctors paid by the Surgeon General also biased?

Web sites, journals and writers also have affiliations with certain organizations and philosophies; these affiliations can affect bias. Before you incorporate a source into your written work, you need to know what its affiliations are and how those affiliations may create bias.

Is it specific? Sweeping generalizations are bad, very bad. Secondary sources using vague language and broad generalizations will adversely affect your arguments and your entire essay. Essays and sources should offer specific evidence and a lot of it.

Is it authoritative? Reliable sources always have an author and clearly identify an author’s experience and education. Many offer a way to contact the author. If you use a source without an author (heaven forbid), the web site or journal should make clear its reasons for publishing the work and as well as a way to contact the author or editor.

When you use secondary sources in your essays...

• They should have expertise in their field.
• Their area of expertise should be a legitimate field of study.
• They should only make claims within the area of their expertise.
• There should be an adequate degree of agreement among experts.
• The author should be identified.