Consider a Source's Origins: Are they Primary or Secondary?
A primary source is a firsthand account written by an eyewitness or a participant. It contains raw data and immediate impressions. For example, primary sources for a large fire caused by a gas leak would include the statements of victims and witnesses, the article written by a journalist who was at the scene, and the report of the fire chief in charge of putting out the blaze.
A secondary source is an analysis of the information contained in one or more primary sources. For example, a second journalist, using the article on the large fire and gas leak as background for a story on industrial accidents, or a historian using the same for a book on urban life in the twentieth century are secondary sources.
For most research papers, both primary and secondary sources will be used. Secondary sources are no less trustworthy than firsthand reports. Remember, eyewitnesses can be prejudiced, self-serving, or simply less informed than a later writer who has synthesized many eyewitness accounts.
In writing a history paper on the attitudes of American social workers toward World War I, you might quote a primary source: Jane Addams, founder of Chicago's Hull House, who was a pacifist. If you relied only on Addams' words alone, however, your reader might get the idea that social workers were unanimously opposed to the war effort. To put Addams' views into perspective, you'd also want to include secondary sources, showing that most of her peers did not identify with pacifism and publicly disagreed with her.
When you find yourself repeatedly citing a fact or source, as quoted in someone else's analysis, it might be wise to go to the primary source from which it came. For example, statistics are often used by both sides arguing an issue-often it's only the interpretation that differs. You might find it useful to go back to the original research (the publication of which is a primary source) and learn where the facts end and the interpretation begins.