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How to Avoid Plagiarism

Northwestern's "Principles Regarding Academic Integrity" defines plagiarism as "submitting material that in part or whole is not entirely one's own work without attributing those same portions to their correct source." Plagiarism can occur in many forms besides writing: art, music, computer code, mathematics, and scientific work can also be plagiarized. This document pays special attention to plagiarism in writing, but it is important to understand that unauthorized collaboration in a math or science assignment is also plagiarism.

In all academic work, and especially when writing papers, we are building upon the insights and words of others. A conscientious writer always distinguishes clearly between what has been learned from others and what he or she is personally contributing to the reader's understanding. To avoid plagiarism, it is important to understand how to attribute words and ideas you use to their proper source. 

Guidelines for Proper Attribution

Everyone in the university needs to pay attention to the issue of proper attribution. All of us--faculty and students together--draw from a vast pool of texts, ideas, and findings that humans have accumulated over thousands of years; we could not think to any productive end without it. Even the sudden insights that appear at first glance to arrive out of nowhere come enmeshed in other people's thinking. What we call originality is actually the innovative combining, amending, or extending of material from that pool.

Hence each of us must learn how to declare intellectual debts. Proper attribution acknowledges those debts responsibly, usefully, and respectfully. An attribution is responsible when it comes at a location and in a fashion that leaves readers in no doubt about whom you are thanking for what. It is useful when it enables readers to find your source readily for themselves. You help them along the way, just as that same source helped you along yours. To make sure that our attributions are useful, we double-check them whenever we can. Quite literally, it is a habit that pays. Colleagues in every field appreciate the extra care. Nothing stalls a career faster than sloppy, unreliable work.

Finally, an attribution is respectful when it expresses our appreciation for something done well enough to warrant our borrowing it. We should take pride in the intellectual company we keep. It speaks well of us that we have chosen to use the work of intelligent, interesting people, and we can take genuine pleasure in joining our name with theirs.

A Note about Attributions or Citations

The two most commonly used attribution systems—Modern Language Assocation (MLA) and American Psychological Association (APA)-- consist of two parts: (a) a reference or works cited list at the end of the document, giving precise information about how to find a source and (b) parenthetical citations immediately following the material you are citing. Professors and disciplines may vary as to the preferred style for documenting ideas, opinions and facts, but all methods insist upon absolute clarity as to the source and require that all direct quotations be followed by a citation. The best solution is to ask which method your instructors prefer. The reference desk of NU's library has manuals available, but form is not as important as substance.

It is sometimes difficult to judge what needs to be documented. Generally, knowledge which is common to all of us or ideas which have been in the public domain and are found in a number of sources do not need to be cited. Likewise, facts that are accepted by most authorities also do not require a citation. Grey areas, however, exist and sometimes it is difficult to be sure how to proceed. Many people wrongly assume that if they find material on the web, that material is in the public domain and does not need to be cited. However, the same guidelines apply to all sources you use in your work: electronic or print, signed or unsigned. If you are in doubt, err on the side of over-documentation.

The following passages come from a number of sources, including undergraduate essays. They are all appropriately documented using Modern Language Association (MLA) style and each represents a different kind of problem that you will be facing in your own written work.

A. Examples of Proper Citation

1. Quoted Material and Unusual Opinion or Knowledge

Source: Vivelo, Jackie. “The Mystery of Nancy Drew.Ms. 3.3 (1992): 76-77. Print.

The teenage detective who was once a symbol of spunky female independence has slowly been replaced by an image of prolonged childhood, currently evolving toward a Barbie doll detective. . . . Every few pages bring reminders of Nancy's looks, her clothing, her effect on other people. . . . The first entry in this series carries a description of Nancy: "The tight jeans looked great on her long, slim legs and the green sweater complemented her strawberry-blonde hair."

Use and Adaptation of the Material:
Nancy Drew has become a "Barbie doll" version of her old self. She has become superficial and overly concerned with her looks. She is described in the new series as wearing "tight jeans [that] looked great on her long, slim legs” (qtd. in Vivelo 77). She has traded her wits and independent spirit for a great body and killer looks (Vivelo 76-77).

The writer has paraphrased most of the material. She discovered that the paraphrased ideas are unusual (not found in other sources). Therefore, she placed a citation at the end of the entire passage. In addition, the writer borrowed a quotation from the Nancy Drew series that she found in the article. The writer has placed quotation marks around that borrowed material and  placed a “quoted in” citation immediately after the quotation.

2. Interpretation

Source: Lehmberg, Stanford. The Peoples of the British Isles: A New History. Vol. I. New York: Wadsworth, 1992. Print.
Page 9: One recent theory, advanced by the physicist Gerald Hawkins, holds that Stonehenge was actually an observatory, used to predict the movement of stars as well as eclipses of the sun and moon. Such a structure would have been of great value to an agricultural people, since it would enable them to mark the changing seasons accurately, and it would have conferred seemingly supernatural powers on the religious leaders who knew how to interpret its alignments.

Use and Adaptation of the Material:
If Stonehenge were  an astronomical observatory which could predict the coming of spring, summer, and fall, this knowledge would have given tremendous power to the priestly leaders of an agricultural community (Lehmberg 9).

The writer has appropriately cited this material since the writer is in debt to someone else for the analysis, even though the writer has not used any direct quotations.

3. Paraphrased Material

Source:   Osborne, Richard, ed. How to Grow Annuals.  2nd ed. Menlo Park: Lane, 1974. Print.
Page 24: As a recent authority has pointed out, for a dependable long-blooming swatch of soft blue in your garden, ageratum is a fine choice. From early summer until frost, ageratum is continuously covered with clustered heads of fine, silky, fringed flowers in dusty shades of lavender-blue, lavender-pink, or white. The popular dwarf varieties grow in mounds six to twelve inches high and twelve inches across; they make fine container plants. Larger types grow up to three feet tall. Ageratum makes an excellent edging.

Use and Adaptation of the Material:
You can depend on ageratum if you want some soft blue in your garden. It blooms through the summer and the flowers, soft, small, and fringed, come in various shades of lavender. The small varieties which grow in mounds are very popular, especially when planted in containers. There are also larger varieties. Ageratum is good as a border plant (Osborne 24).

The writer has done a good job of paraphrasing what could be considered common knowledge (available in a number of sources), but because the structure and progression of detail is someone else's, the writer has acknowledged the source. This the writer can do at the end of the paragraph since he or she has not used the author's words.

4. Using Other Authors' Examples

Source: Begley, Sharon. "The Puzzle of Genius." Newsweek 28 June 1993: 46+. Print.
The creative geniuses of art and science work obsessively. . . .  Bach wrote a cantata every week, even when he was sick or exhausted.

Source: Hotz, Robert. “The Heady Theories on Contours of Einstein's Genius.” Wall Street Journal 2009 May 22, late ed: A9. Print.
Although he published 300 scientific papers, Einstein couldn't easily describe the way his mind worked.

Use and Adaptation of the Material
If there is a single unifying characteristic about geniuses, it is that they produce. Bach wrote a cantata every week (Begley 50). Einstein drafted over 300 papers (Hotz A9).

Instead of finding original examples, the writer has used other authors’ example to back up what the writer had to say; therefore, the writer cited the sources where he found the examples.

5. Using Other Authors' Charts and Graphs

Source: Technorati. State of the Blogosphere 2008.  Technorati, 13 October 2009. Web. 20 November 2009

example graph

Use and Adaptation of the Material:

As blogging has evolved, so has its credibility as a communication medium. In its survey for its 2008 State of the Blogosphere Report, Technorati asked a statistically valid representative sample of bloggers world wide about the credibility of the blogging world. The results suggest blogging is becoming more credible as a source of information (see Figure 1).

example graph

Figure 1: Perceptions of Blogs and Traditional Media. Source: Technorati 2008.

Instead of creating an original chart or graph, the writer has used one from an outside source to support what the writer has to say; therefore the graph has been cited both in the textual introduction and also in the caption. If the writer had created an original chart, some of the facts might need citations (see example VIII).

6. Using Class Notes

Source: McKay, Mary. : “Messages in Modern Music.” Northwestern University.  Evanston, IL.  10 Mar. 2010.  Lecture.
A. Born in USA--Springsteen's 7th, most popular album
a. Recorded with songs on Nebraska album--therefore also about hardship
1. Nebraska about losers and killers
b. About America today--Vietnam, nostalgia, unemployment, deterioration of family
c. Opening song--many people missed the Vietnam message about how badly vets were treated.
class notes--Messages in Modern Music A05
Professor Mary McKay--March 10, 2010

Use and Adaptation of the Material:
As Professor McKay has pointed out, many of the songs in Born in the USA (Springsteen's seventh and most popular album), including the title song, were recorded with the songs on Nebraska. Consequently, Born in the USA is also about people who come to realize that life turns out harder and more hurtful than what they might have expected. However, while Nebraska deals with losers and killers, Born in the USA deals more locally with the crumbling of American society--its treatment of returning Vietnam veterans, its need to dwell on past glories, its unemployment and treatment of the unemployed, and the loss of family roots. This is apparent from the opening song of the album "Born in the USA" in which Springsteen sings from the perspective of a Vietnam Veteran.

By mentioning Professor McKay’s name in the text itself, the writer has acknowledged that these ideas (which are not commonly held or the writer has not investigated to find out if they are commonly held) come from a lecture. In this instance, because there is no page number to cite, no parenthetical citation is necessary. A reader can go to the entry for McKay in the Works Cited list to find all the necessary specific information about the source.

7. Debatable Facts

Source: Craig, Gordon A. Europe Since 1815. New York: Dryden, 1974. Print.
Page 370: In the campaigns of 1915, Russian casualties have been conservatively estimated at more than 2 million.

Source: Stavrianos, Leften.S. The World Since 1500. New York: Prentice Hall, 1966. Print.
Page 438: By the end of the summer [of 1915] in addition to military casualties totaling 2,500,000 men, Russia had lost 15 percent of her territories. . . .

Response to the Material
Estimates of the number of deaths in Russia during 1915 range from over two million (Craig 370)  to two and a half million (Stavrianos 438).

The writer found different facts in different sources; therefore the "facts" needed to be documented.

8. Unusual Facts

Source: Enroth-Cugell, Christina, Lyle F. Mockros, and Robert A. Linsenmeier. “Biomedical Engineering at Northwestern, 1969-1999.” PDF File. Northwestern University Biomedical Engineering. Northwestern University, 4 Sept. 2001. Web. 3 August 2010.
The majority of the biomedical engineering faculty from various departments in Tech believed that if the program at Northwestern was to maintain the worldwide reputation for excellence it had achieved and make further progress during the ensuing years, then the curriculum had to continue to include quantitative biology courses on the Evanston Campus. One compelling reason for advocating the reintroduction of such biology courses on the Evanston campus was that by the early 1970's approximately 40% of first year undergraduates in the engineering school were enrolling in the Interdisciplinary Biomedical Engineering Program.

Use and Adaptation of the Material:
For decades, biomedical engineering has been one the most popular engineering majors at Northwestern. In fact, in the 1970’s roughly 40% of incoming engineering undergraduates entered the Interdisciplinary Biomedical Engineering Program (Enroth-Cugell, Mockros and Linsenmeier, 3)

The writer found this fact in only one source and wants his reader to know where to find it.

B. Examples of Plagiarism

Failure to acknowledge the sources from which we borrow ideas, examples, words and the progression of thought constitutes plagiarism. Here are some examples.

1. Direct Plagiarism

Source Material
From: Ekman, Paul, Wallace V. Friesen, and Phoebe Ellsworth.  Emotion in the Human Face: Guidelines for Research and an Integration of Findings. New York: Pergamon, 1972. Print.

Page 1: The human face in repose and in movement, at the moment of death as in life, in silence and in speech, when alone and with others, when seen or sensed from within, in actuality or as represented in art or recorded by the camera is a commanding, complicated, and at times confusing source of information. The face is commanding because of its very visibility and omnipresence. While sounds and speech are intermittent, the face even in repose can be informative. And, except by veils or masks, the face cannot be hidden from view. There is no facial maneuver equivalent to putting one's hands in one's pockets. Further, the face is the location for sensory inputs, life-necessary intake, and communicative output. The face is the site for the sense receptors of taste, smell, sight, and hearing, the intake organs for food, water, and air, and the output location for speech. The face is also commanding because of its role in early development; it is prior to language in the communication between parent and child.

Misuse of source
(italicized passages indicate direct plagiarism):
Many experts agree that the human face, whether in repose or in movement, is a commanding, complicated, and sometimes confusing source of information. The face is commanding because it's visible and omnipresent. Although sounds and speech may be intermittent, the face even in repose may give information. And, except by veils or masks, the face cannot be hidden. Also, the face is the location for sensory inputs, life-supporting intake, and communication.

The plagiarized passage is an almost verbatim copy of the original source. The writer has compressed the author's opinions into fewer sentences by omitting several phrases and sentences. But this compression does not disguise the writer's reliance on this text for the concepts he passes off as his own. The writer tries to disguise his indebtedness by beginning with the phrase "Many experts agree that. . . . " This reference to "many experts" makes it appear that the writer was somehow acknowledging the work of scholars "too numerous to mention." The plagiarized passage makes several subtle changes in language (e.g., it changes "visibility and omnipresence" to "it's visible and omnipresent"). The writer has made the language seem more informal in keeping with his own writing style. He ignores any embellishments or additional information given in the source-passage. He contents himself with borrowing the sentence about how only masks and veils can hide the face, without using the follow-up elaboration about there not being a "facial equivalent to putting one's hands in one's pockets." He also reduces the source's list of the face's diverse activities at the end of the paragraph.

Had the writer enclosed the borrowed material in quotation marks and credited the authors of the Emotions book with a parenthetical citation, this would have been a legitimate use of a source.

2. The Mosaic

Source Material
From: Fishman, Joshua. Language in Sociocultural Change. Stanford: Stanford University Press, 1972. Print.

Page 67: In a relatively open and fluid society there will be few characteristics of lower-class speech that are not also present (albeit to a lesser extent) in the speech of the working and lower middle classes. Whether we look to phonological features such as those examined by Labov or to morphological units such as those reported by Fischer (1958) (Fischer studied the variation between -in' and -ing for the present participle ending, i.e. runnin' vs. running and found that the former realization was more common when children were talking to each other than when they were talking to him, more common among boys than girls, and more common among "typical boys" than among "model boys"), we find not a clear-cut cleavage between the social classes but a difference in rate of realization of particular variants of particular variables for particular contexts. Even the widely publicized distinction between the "restricted code" of lower-class speakers and the "elaborate code" of middle-class speakers (Bernstein 1964, 1966) is of this type, since Bernstein includes the cocktail party and the religious service among the social situations in which restricted codes are realized. Thus, even in the somewhat more stratified British setting, the middle class is found to share some of the features of what is considered to be "typically" lower-class speech. Obviously then, "typicality," if it has any meaning at all in relatively open societies, must refer largely to repertoire range rather than to unique features of the repertoire.

Misuse of source
(italicized passages indicate direct plagiarism):
In a relatively fluid society many characteristics of lower-class speech will also be found among the working and lower middle classes. Labov and Fischer's studies show that there is not a clear-cut cleavage between social classes but only a difference in the frequency of certain speech modes. All classes share certain speech patterns. The difference among classes would only be apparent by the frequency with which speech expressions or patterns appeared. By this standard, then, Bernstein's distinction between the "restricted code" of the lower-class speakers and the "elaborated code" of middle-class speakers is useful only up to a point, since Bernstein mentions cocktail parties and religious services as examples of "restricted speech" groupings. "Typicality" refers more to speech "range" than to particular speech features.

While this passage contains relatively few direct borrowings from the original source, all its ideas and opinions are lifted from it. The writer hides her dependency on the source by translating its academic terms into more credible language for a novice in sociology. For example, the plagiarist steers clear of sophisticated terms like "phonological features," "morphological units," and "repertoire range." However, her substitutions are in themselves clues to her plagiarism, since they over-generalize the source's meaning. The writer seems to acknowledge secondary sources when she refers to Labov's and Fischer's studies, but she obviously has no first-hand knowledge of their research. If she had consulted these studies, she should have cited them directly and included them in the Works Cited list, rather than pretending that both she and her audience would be completely familiar with them. She intertwines her own opinions with the source and forms a confused, plagiarized mass.

The writer should have acknowledged her indebtedness to her source by eliminating borrowed phrases and crediting her paragraph as a paraphrase of the original material. She could also have put quotation marks around the borrowed phrases and cited them appropriately: “As Fishman explains, phonological studies by Labov and Fischer show that “there is not a clear-cut cleavage between social classes but only a difference” in the frequency of certain speech modes (Fishman 67).

3. Paraphrase

Source : The Sun Also Rises by Ernest Hemingway. Cliffs Notes, n.d. Web. 4 August 2010.

If the old traditional values are no good anymore, if they will not serve man, what values then will serve man? Hemingway rejects things of abstract qualities courage, loyalty, honesty, bravery. These are all just words. What Hemingway would prefer to have are concrete things. For Hemingway a man can be courageous in battle on Tuesday morning at 10 o'clock. But this does not mean that he will be courageous on Wednesday morning at 9 o'clock. A single act of courage does not mean that a man is by nature courageous. Or a man who has been courageous in war might not be courageous in some civil affair or in some other human endeavor. What Hemingway is searching for are absolute values, which will be the same, which will be constant at every moment of every day and every day of every week.
Ultimately, therefore, for Hemingway the only value that will serve man is an innate faculty of self-discipline. This is a value that grows out of man's essential being, in his inner nature. If a man has discipline to face one thing on one day he will still possess that same degree of discipline on another day and in another situation. Thus Francis Macomber in the short story "The Short, Happy Life of Francis Macomber," has faced a charging animal, and once he has had the resolution to stand and confront this charging beast, he has developed within himself a discipline that will serve him in all situations. This control can function in almost any way in a Hemingway work.

Misuse of source:
Hemingway tries to discover the values in life that will best serve man. Since Hemingway has rejected traditional values, he himself establishes a kind of "code" for his heroes. This code is better seen than spoken of. The Hemingway hero doesn't speak of abstract qualities like courage and honesty. He lives them. But this living of values entails continual performance the Hemingway hero is always having his values put to the test.

How can the hero be up to this continual test? Hemingway stresses the faculty of self-discipline as the backbone of all other virtues. Self-discipline places man's good qualities on a continuum. The dramatic change in Francis Macomber in "The Short, Happy Life of Francis Macomber" stems more from his new-found self-control than from any accidental combination of traits.

This illustrates plagiarism since the writer used the notion of the "Hemingway code hero" presented in Cliffs Notes as the sole basis for his own essay. He has absorbed his source's concepts, re-phrased them, and, perhaps, made them simpler. But there is a one-to-one relationship between the development of ideas in the Cliffs Notes and the plagiarist’s rendition.

The first two sentences of the plagiarist's are directly borrowed from his source; the remaining sentences are more artfully disguised. The worst feature of this idea-copying is that it seems to be the end product of a close reading of Hemingway's "Short, Happy Life," the writer makes it appear that his comments are based on this short story.

The writing here would be acceptable if he had written the same paraphrase with the proper acknowledgement of his source.

4. Insufficient Acknowledgement

Source: Laven, Peter. Renaissance Italy: 1464-1534. New York: Capricorn, 1964. Print.

The tenacious particularism of the Italian state gave rise to a wide variety of constitutional solutions and class structures throughout Italy. Even conquered territories and those swallowed up by bigger neighboring powers often managed to retain much of their internal organization as it had been. If power changed hands, the instruments and forms of power usually remained the same. Since the economic needs of such territories did not suddenly alter with a change of government or master, those classes which had been important before the change tended to continue to be important afterwards as well. Only when the nature of the change was economic and social might there have been a reversal in the relationships of classes; but even in this there was no sudden revolution in the structure of classes.

Misuse of source:
In his comprehensive study, Renaissance Italy, Peter Laven discusses the peculiar organization of Renaissance city-states: “The tenacious particularism of the Italian states gave rise to a wide variety of constitutional solutions and class structures throughout Italy. Even conquered territories and those swallowed up by bigger neighboring powers often managed to retain much of their internal organization as it had been”(130). This means that if power changed hands, the instruments and forms of power usually remained the same. Since the economic needs of such territories did not suddenly alter with a change of government or master, those classes which had been important before the change tended to continue to be important afterwards as well. Only when the nature of the change was economic and social might there have been a reversal in the relationships of classes; but even in this there was no sudden revolution in the structure of classes.

This half-crediting of a source is a common form of plagiarism. It stems either from a desire to credit one's source and copy it too, or from ignorance as to where to footnote. The general rule is to footnote after rather than before your resource material. In this case, the plagiarist credits historian Peter Laven with two quoted sentences and then continues using the author without giving acknowledgement. The writer disguises the direct plagiarism as a paraphrase by using the falsely-explanatory phrase "This means that ..." in the third sentence. This example of plagiarism is especially reprehensible because the writer seemingly acknowledges his source--but not enough.

This guide was prepared with contributions from many people, including members of the Undergraduate Council. Mark Sheldon, Assistant Dean for Academic Integrity in WCAS, assisted with the organization of the document and worked with Barbara Shwom of the WCAS Writing Program to update the material. The section on attribution was written by Jean Smith of the WCAS Writing Program, with help from Bob Wiebe of the History Department. Contributors include Katrina Cucueco (Speech '96), Ryan Garino (CAS '98), Scott Goldstein (Tech '96), and Jean Smith and Ellen Wright of the Writing Program. The examples of plagiarism and comments are based upon Sources: Their Use and Acknowledgement (published by Dartmouth College).

For more on plagiarism, see Charles Lipson, Doing Honest Work in College. How to Prepare Citations, Avoid Plagiarism, and achieve Real Academic Success (Univ. of Chicago Press, 2004).