Many students wonder whether they need to include a citation for every sentence they write that doesn't represent their own original thoughts. In fact, citations are not always necessary. Use the guidelines below to determine whether you need to cite a source in a particular situation. When in doubt, err on the site of caution and include a citation, or check with your instructor.
Most of these rules are fairly straightforward. However, it can be difficult for students to recognize when a piece of information is "common knowledge," and therefore requires no citation. When in doubt, use the following test: is the information widely available in many sources? For example, would a general encyclopedia entry about the subject include this piece of information? If so, it need not be cited.
Since these are factual statements, no citation is needed.
Since this statement describes an event that undeniably occurred in the novel David Copperfield, no citation is necessary, even if this sentence was inspired by something you read in a book or journal article.
This idea is widely accepted in the field of economics, and therefore you would not need to include a citation for this sentence in an economics paper. But if you make this statement in a psychology paper, you should include a citation, most likely to a textbook or reference work in economic theory. Understanding what is common knowledge in your field of study requires experience; ask your instructor if you are unsure whether something needs to be cited.
On the other hand, if you read a source that offers opinion or interpretation regarding something that is common knowledge, and decide to incorporate this perspective into your paper, you must cite the source. Here are some examples:
All of these statements require a citation.
One of the best practices for preventing plagiarism starts long before you begin writing your paper or presentation. It can be boiled down to this: keep your research organized. By the time you start your paper, if you have complete citations attached to every "borrowed" idea or passage that you may use, you will be much less likely to commit plagiarism. There will be no last-minute hunting for citations, which creates a temptation to either invent citation information or pass of an idea as your own. Furthermore, if your research notes clearly indicate which ideas were paraphrased or quoted from other sources, you are less likely to accidentally use another's ideas or words without attribution.
There are two parts to this process.
While doing your research, record the citation information for every source that you might use. To learn how to locate citation information in online catalog or journal database records, see our guide to Understanding Citations. Here is a checklist showing what you will need for most citation styles:
Here are some tips to help you with the process of gathering citations:
While reading your sources, take notes on any passages that you might want to quote, paraphrase, or summarize in your paper. This can be done either in a Word document or on individual notecards for each passage. Since sloppy note-taking frequently leads to inadvertent plagiarism, try following the suggestions below:
Keep all your printed sources, research notes, outlines and drafts until you receive your final grade. If you are accused of plagiarism, these items may be requested as evidence. If you have followed the guidelines above, these documents may demonstrate your innocence!
As the previous section explains, good research requires excellent organization and record-keeping. Good organization also helps you avoid unintentional plagiarism. When you have completed most of your research and you are ready to draft your paper, you will need to learn how to incorporate ideas from your sources accurately, correctly, and honestly.
When you summarize, paraphrase, or quote from a course you must provide a citation. So, in this sense, summary, paraphrase, and quotation are similar: each of these ways to use your sources requires citation. But these three techniques are also significantly different from each other. You will choose among these techniques by deciding what you intend to accomplish with your source material.
A summary expressed on the main points of a source or part of a source. It is a brief, condensed version of the ideas in the source. You might summarize if you want to show the primary point of one section of an article or provide a general overview of the source material. Here is one example of a very brief summary which shows the main point of one section of the following source:
Fussell, Elizabeth. "Constructing New Orleans. Constructing Raze: A Population History of New Orleans." Journal of American History 94.3
(2007): 846-856. Print.
From its founding in the early 1700s, New Orleans has been a multicultural city, but the racial and cultural composition of its population has shifted and changed a great deal over time. Slaves and former slaves, European colonists and immigrants, whites, Creoles, Haitians and African-Americans--all can claim an important part in the city's history. |
A longer summary might consist of six to ten sentences or more, perhaps with the purpose of presenting an overview of a source or detailed background material relevant to your paper. For example, this summary covers an author's very long description of the changes in the cultural make-up of New Orleans in the past 250 years.
Since the early 1700s, the population of New Orleans has experienced racial and cultural shifts that have been caused primarily by social and economic factors. At its French founding, New Orleans was a city inhabited by the slaves who essential built it. It grew for two centuries, leading up to and through its acquisition by the U.S., as a population largely made up of descendants of slaves, white French colonists, Creoles and ex-slaves from Haiti, and European immigrants who moved to New Orleans in search of work. Growth slowed in the twentieth century, when the Jim Crow era resulted in division of New Orleans into segregated white and black societies, and large-scale flight of the white population to the suburbs left the city with a black majority from the 1960s through most of the 1980s. In its most recent state-since Hurricane Katrina in 2005--the city first emptied, then became repopulated with white and black former residents and new Latino migrant workers (Fussell 847, 8520-853). |
Many students think of paraphrasing as what you do when you read a source and then "put it in your own words." This concept is somewhat accurate, but it's not the best way to think about paraphrasing. You should not be trying to find replacement words whose meaning is identical to the language of the source, and then simply put the new words precisely into the place of the original words. That's very hard to do, and often it results in roundabout, lumpy sentences that don't really make a lot of sense. What if you read that "Therapy dogs provide physical and emotional comfort to the elderly in rehabilitation facilities." You would never want to write in your essay, "Healing canines bring rest and repose to old people in hospitals." If you do so, you make your sentences like math equations--plugging in words that you think are equivalent to other words. These are usually not good sentences.
When you paraphrase a source, you are not rewording so much as restating or recasting the idea in your own voice, your language, and in a context that assists the purpose of your paper. Here are some examples:
Original source: Jerry Adler. "Thinking Like a Monkey." Smithsonian January 2008: 58-62. Print. "Santos's interest here is in what psychologists call 'theory of mind,' the ability to impute thought and intentions to another individual, one of the cornerstones of human cognition...As recently as a decade ago, the conventional wisdom doubted that even chimpanzees, which are more closely related to humans than are monkeys, possessed theory of mind. This view is changing, in large measure because of Santos and her collaborators...The experiment relies upon one of the most predictable traits of rhesus monkeys: their tendency to steal food at every opportunity. Santos discovered this a few years ago when she and her colleagues were running experiments in cognition and tool use involving lemons, and frequently had to quit early because the animals stole all the fruit. The island's monkeys are supplied with food, of course, and they also forage, but to leave so much as a raisin unguarded is to invite larceny; the researchers eat their own lunches inside a locked cage of cyclone fencing. The theory-of-mind experiment is designed to test whether the monkeys, who obsessively guard their own food, assume that people do the same." Paraphrase: Recently, researchers have studied the intelligence of monkeys through the monkeys' ability to understand that other creatures |
You see, this passage is not a summary of the article because it does not cover all of the author's main points, such as the methodology of the experiment or its specific results. It doesn't even cover all of the main ideas of one section of the article. The new passage is a paraphrase because it expresses the source's idea--the purpose and description of the thieving monkey experiment--in language that is largely different from the language of the source.
On occasion, you will choose to include the exact words--word for word--of your source. Quoting your source is selecting a very brief passage, sentence, phrase or term from the original source to use in your paper. YOu will do so when you want to include the exact language of the source's author for any of a number of reasons: (1) the wording of the source is particularly apt or concise, and, as a result, it will be very appropriate and precise for your paper; (2) the wording of the source is expressed particularly well; that is, the words themselves are well-spoken, persuasive, or especially powerful; (3) the language of the source provides terms or phrases that are field-specific and have very precise definitions or meanings.
Original source: Laurie, John and Stephen Buckman. "WiFi as a backend." Economic Development Journal 7.4 (2008): 12-17. Print. "As technology advances and becomes more integrated into people's lives, cities are increasingly becoming a digitized, fragmented environment that results in a dichotomy of separation and togetherness. The advent and expansion of the internet...accelerates both spatial concentration and decentralization. In theory, the internet allows people to live and work wherever they choose and yet stay connected with society at large...Communities have been traditionally defined by spatial parameters. The internet is dissolving these traditional spacial parameters, yet it could be argued that Wireless (WiFi) internet is actually helping to reestablish traditional spatial communities." Quotation: Though many people feel that technology is electronically connecting but physically separating people, the growth of internet cafes and cities' use of wireless networks make it possible to say that the internet "is actually helping to reestablish traditional spatial communities." |
Frequently, you will write sentences and paragraphs that use the techniques of paraphrase and quotation as you refer to ideas from your sources. Careful use of paraphrasing can help you refer to material that you prefer not to quote word-for-word. Quoting allows you to retain the exact words, terms, and expressions of the original author. Here is another example from a recent article about the discipline of Economics within the liberal arts curriculum:
Original source: Colander, David, and Kimmarie McGoldrick. "The Economics Major and Liberal Education. Liberal Education 95.2 "It is worthwhile to teach 'big-think' questions, but because they do not fit the disciplinary research focus of the profession, they tend not to be included in the economics major. This is regrettable, since struggling with the "big-think" questions helps provoke a passion for learning in students and, hence, can be a catalyst for deeper student learning. It is similarly worthwhile to expose students to longstanding debates within the field. For example, Marx considered the alienation created by the market to be a central problem of western societies. Hayek argued that the market was necessary to preserve individual freedom....Such debates are highly relevant for students to consider as they study economics within the context of a liberal education. But these kinds of debates are not actively engaged as part of cutting-edge research, which instead tends to focus on narrow questions that can be resolved through statistical analysis or on highly theoretical questions that exceed the level of undergraduate students." Paraphrase or Quotation: One of the most important qualities of a small liberal arts college is the emphasis on the type of thought-provoking questions that not only help students learn academic material, but also help them to learn about the important ideas that have shaped our culture. Colander and McGoldrick calls these "big-think" questions, which are often not addressed at institutions that focus too narrowly on the research dimension of the discipline (22). For example, about the discipline of Economics, the two professors assert that it is "worthwhile to expose students to longstanding debates within the field." but at most large institutions "these debates are not actively engaged as part of cutting-edge research," and, as a result, students miss out on classroom approaches that can "help provoke a passion for learning...and be a catalyst for deeper student thinking" (Colander and McGoldrick 22). |
The first citation above marks the end of a sentence that includes material paraphrased from page 22 of the original. The second citation also refers to material from page 22, which is directly quoted in the paragraph.
As you see, paraphrased and quoted material always requires citations. But different academic disciplines use different style guides as the standards for presenting and formatting those citations and a paper's bibliography. The next section will give you some examples of citations in a few of the most widely used documentation styles. It will also direct you to a page that demonstrates documentation comprehensively and provides information about all of the documentation styles used in college courses.
When you begin any assignment that involves research, you will always need to know which documentation style is expected by the discipline and professor of your course. The citations provided in the examples above adhere to MLA style, which is the documentation and bibliographic style described in the MLA Handbook for Writers of Research Papers. Your courses may require assignments to use MLA style, or they may require another documentation style, such as APA, Chicago/Turabian, ASA, ACS, CSE or another documentation style. The formats of these differ as the values of the disciplines differ. For example, in the sciences, parenthetical references always include dates because scientific research develops over time, and the date of a study is very important.
For every documentation style, you will need to always have a few important things in mind:
Here are some examples of how citations and bibliographic entries would look as formatted in two of the most common documentation styles. Let's use the Smithsonian article about the monkeys who steal food.
In-text parenthetical references (or "parenthetical citations")
MLA style:
According to the study, some monkeys act as if a human thinks like a monkey. If they do, then monkeys exhibit "theory-of-mind," which is "the ability to impute thought and intentions to another individual, one of the cornerstones of human cognition" (Adler 60). |
APA style:
If they do, then monkeys' exhibit "theory-of-mind," which is "the ability to impute thought and intentions to another individual, one of the cornerstones of human cognition" (Adler, 2008, p. 60). [If this passage paraphrased the original source rather than quoting it, the page number would be omitted and the citation would be (Adler, 2008).] |
Bibliographic entry
MLA style:
Adler, Jerry. "Thinking Like a Monkey." Smithsonian 38.10 (2008): 58-62. Print. |
APA style:
Adler, J. (2008). Thinking like a monkey. Smithsonian, 38(10), 58-62. |
Certain documentation styles always use footnotes or endnotes, not parenthetical citations. For example, in Chicago's Notes/Bibliography style, a quoted passage or paraphrased material would be cited in a footnote, like this:
Recently, researchers have studied the intelligence of monkeys through the monkeys' ability to understand that other creatures think. Because rhesus monkeys are known to be skillful food thieves, Laurie Santos and her students used the monkeys' bad habit to find out if a monkey tries to imagine what a person is thinking in order to try to steal that person's food. According to the study, some monkeys act as if a human thinks like a monkey.1 |
1 Jerry Alder, "Thinking Like a Monkey," Smithsonian 38 (2008): 60.
For more information on documentation styles, including links to web resources with helpful examples and guidelines for each style, see Geisel Library's webpage on Citing Sources.