Beginning researchers often ask, "Do I have to cite everything?" This is a good question because not every piece of information in a research paper must be cited. Figuring out what to cite and what not to cite can sometimes be difficult, even for experienced researchers. Generally, if you are unsure, include a citation. It’s always better to have an unnecessary citation in your paper than to omit one that is necessary.

Here are some general guidelines for materials that usually don’t require acknowledgment in research projects:

• Common knowledge. It’s often easy to spot pieces of common knowledge. The sky is blue, the United States has fifty states, the 1996 presidential candidates were Bill Clinton and Bob Dole-these are all pieces of information that appear in various sources, but because they are known to just about everyone, they are not ideas that must be cited. However, sometimes recognizing common knowledge becomes trickier because common knowledge for one person may not be common knowledge for another. For example, it is common knowledge among educators that Paolo Freire came up with an idea he called "the banking concept of education." Someone writing for an audience of educators could probably use this phrase without citing it, because the reference to Freire is clear. However, if this writer were addressing a more general academic audience, she should include the citation, or she might give the impression that the idea is her own. Note that identifying your audience is the key to recognizing common knowledge. If you know what audience you are writing to, you will have a clearer idea of what your readers would consider common knowledge. As always, if you are unsure, be more conservative rather than less. Include the citation, and then ask your teacher or another resource if the citation seems necessary.
• Fact. Uncontested pieces of information that can be found in many different sources-particularly reference sources such as encyclopedias-do not require acknowledgment. Andrea Lunsford gives an example in The St. Martin’s Handbook of one such fact: that most of the Pearl Harbor military base, except oil tanks and submarines, was destroyed on December 7, 1941, by Japanese bombers. She adds an example of information on the same topic that does require citation: "a source that argued that the failure to destroy the submarines meant that Japan was destined to lose the subsequent war with the United States" (394). The distinction Lunsford makes here is between fact-something commonly accepted as true-and opinion-something that is arguable.
• Your own ideas. This kind of information can be difficult to recognize, especially during the research process, when you are reading and absorbing so many others’ ideas. A good way to capture your own ideas is to write a draft before you begin researching. Anne Herrington and Charles Moran, who are professors at the University of Massachusetts-Amherst, call this sort of draft an "instant draft." It can serve as a helpful record of your own knowledge and opinions at the start of a project as well as a way to get started writing early. See the section "Taking Notes and Putting Information in Your Own Words" for more details on how to write an instant draft.
• Your own field research. Knowledge that you create by conducting a field study such as a survey, interview, or observation is considered your own work. This sort of information does not need to be cited. However, another kind of ethics guides the field researcher. You should be clear about how you collected the information. In addition, you should be scrupulous about protecting your participants’ autonomy (be sure to quote them accurately, and ask for their feedback when possible) and privacy (use pseudonyms, and omit identifying information).

Commonly consulted sources for research projects include books, articles from journals or newspapers, and Web sites. Keep in mind that some of your sources may be somewhat unusual, such as information from an Internet multiuser domain (MUD), an interview you conduct yourself, or the instruction manual for a model ship kit. Everything that you draw from another source, unless it falls into one of the categories described above (common knowledge, fact, your own ideas, and your own field research), must be cited.

Your citations should appear in two places: first, in the body of your paper, and second, in a list at the end of the paper. The style of citation your teacher has asked you to use will affect the formatting of these citations. For example, in Modern Language Association (MLA) style, your in-text citations should include the author’s last name and the page number where the information can be found; complete bibliographic information for each source will appear in a section titled "Works Cited." You can think of citations as a kind of map for your reader. An in-text citation guides the reader to the "Works Cited" section so that she can see where a particular idea came from. The "Works Cited" section gives precise directions on how to find the source itself. You can find detailed information on citation styles in a handbook.

The following list is not exhaustive, but suggestive. New kinds of information are always emerging: For instance, one of my students recently asked me how to cite the information she found on the label of an aspirin bottle! Generally speaking, however, here are guidelines for which materials require acknowledgment in academic writing:

• Another person’s words. Direct quotations must always be cited.
• Another person’s ideas. Even if you rephrase someone else’s idea by paraphrasing or summarizing it, it must be cited. Citations for paraphrases and summaries look just like citations for quotations, except that there are no quotation marks involved.
• Judgments, opinions, and arguments. Arguable information, such as the idea about the effect of the Pearl Harbor bombing discussed in the section "Fact," must be cited. Any time you offer an idea from another source that could be argued, acknowledge that it is this individual’s point of view. Note that you should do this even if you thought of the idea, then encountered it through your research. You can indicate in your writing that you came to the idea independently of the other author, but you cannot omit mention of the other author.
• Visual information. If you use a chart, graph, or picture from another source-or if you use the information from that chart, graph, or picture-acknowledge the source.
• Information that can be attributed to a company or organization rather than a single person. This is often the case with Web pages, which tend not to list individual authors. In this case, the organization that sponsored the publication should be listed as the author. If an author is unknown, as in an anonymous manuscript, your citation should indicate that. Depending upon the citation style you are using, you may begin such a citation with "Anonymous" instead of the author’s name, or you may cite only the title of the source. Again, consult a handbook for specific guidelines when using specific citation styles.
• Information gathered from class lectures or from another aural source. If you heard it rather than saw it, you must still cite it. There are various ways to cite information you’ve heard, including as a lecture, as a personal communication, or as an interview.
• Opinions offered by readers. Usually, as you work on a research project, you’ll get feedback from others-your teacher, classmates, and friends. This kind of information should be acknowledged, too. For example, suppose that you are working on a paper about Wiccan traditions and a classmate offers you his opinion that Wiccan traditions will be as common as Christianity in another two hundred years. Cite his idea by quoting or paraphrasing him.
• General help offered by readers. Sometimes the feedback you receive from a reader will affect the shape of your essay, but not its content. For instance, your classmate might offer the suggestion that you include a personal anecdote to add more interest to your introduction. In this case, the best way to acknowledge your classmate’s contribution is in a note of thanks appended to the paper. Such "Acknowledgments" notes generally appear at the end of academic papers, or in a footnote added to the title or first paragraph. Look at a refereed journal in your discipline and you’ll see examples of less-formal acknowledgments of this kind.