Many papers you'll write in college require "peer-reviewed articles." The "peers" reviewing these articles are experts in the same field as the author; for instance, physics professors will review a physics professor's article.
A professor or other expert submits their article to the editor of a journal in their field. For instance, a psychology professor might submit an article to the Journal of Abnormal Psychology. A physicist would submit a paper to Applied Physics journal. The editors of these academic journals then ask the authors' peers - other professors or experts in this field - to evaluate the submitted articles. Those experts then submit their comments and reviews back to the editor, who returns them to the author, who answers the criticisms and rewrites portions of the article to satisfy his "peer" reviewers.
You can see why this review of articles would takes months or years. This lengthy review process explains why peer-reviewed journals - also known as scholarly or academic journals - publish only two or four times a year.
Your instructors want to know you can find peer-reviewed articles. This means using limiters to narrow your search results in databases to find these articles. Librarians can help you with this. Databases vary greatly and each offers different features. We can't cover them all here, but we can use a search in one of the more widely used databases as an example. Start from the library's homepage and click on the "Articles" tab, shown in black in the illustration below. From the left drop-down menu, we'll use a database that includes nearly 4,000 full-text, peer-reviewed journals, Academic Search Complete, highlighted in blue, above.
Once in the database, you will notice words and phrases filling in below what you are typing in the search field. This means that articles containing those subject terms (also called thesaurus terms) are in the database. Adding the related terms highlighted in blue below retrieved articles the student wanted; in fact, more than he could reasonably use.
The next challenge is refining your search. The student wanted to write about how animal assisted therapy was used to help veterans. That's where the Boolean operators, AND, NOT or OR, which are built into the database will help. Using AND to add "veterans with PTSD" and using NOT to exclude PET scans, the student refined his search to articles for his paper. His instructor also required peer-reviewed articles of recent research, often meaning limiting to the last five or ten years. Here is how you find those.
On the left-hand side of the page in the illustration below, you will see "Limit To" above small boxes next to Full Text and Scholarly (Peer Reviewed) Journals and a slider bar with search fields for Publication Date.
Adding more specific search terms, using Boolean operators AND and NOT and limiters Full-Text, Peer-Reviewed and Publication Date netted this student 16 articles to read on his topic, as you see below. The most important step is to allow yourself enough time to read the articles you find.
Professional researchers spend their days searching databases and perfecting ways to achieve better search results. An often-stated goal is "the perfect 30-item search," enough results to give you a wide view of a topic but not so many as to be overwhelming. Don't be discouraged if your first few searches seem complicated or unsuccessful. Keep trying different search terms and allow enough time to peruse your results. Come to the library for help at the reference desk and ask your instructor if your class can have a class in the library classroom.