Q: What does "peer-reviewed" mean?
A: If an article has been peer-reviewed before being published, it means that the article has been reviewed by other scholars in the same field of study ("peers").
The reviewers have commented on the article, not only noting typos and possible errors, but also giving a judgment about whether the article has been researched and written well (the authors are building on other reliable research, the methods for the study are good and authors are drawing appropriate conclusions..)
Q: If a piece of information wasn't peer-reviewed, does that mean that I can't trust it?
A: No. Many newspapers and magazines do fact-checking. Government web sites like census.gov and cdc.gov are trustworthy and have excellent data and statistics. Consult and use a variety of sources to verify the information. When in doubt, ask your instructor or a librarian.
Q: How do I find a peer-reviewed article?
A: Start in the library's databases or "Find It" search and check the "peer-reviewed" checkbox. Then look the article over for signs like: the authors have PhD or MD degrees; the article has an abstract and is trying to answer a research question or hypothesis; and the article has many references at the end. If in doubt, ask a librarian or your instructor.
Q: If I get an article from a peer-reviewed journal, that means it's peer-reviewed, right?
A: No, there are other types of articles in peer-reviewed journals: