Plagiarism Guide

What is Plagiarism?
Specific Examples
Avoiding Plagiarism
Other Resources
Real-World Cases



1. What is plagiarism?  Blatant vs. Inadvertent.

      At the most basic level, plagiarism is presenting someone else's work as your own. This definition, however, is not always useful in helping students and inexperienced writers distinguish when they are plagiarizing from when they are legitimately presenting information learned from a specific text.

      Plagiarism is perhaps a greater potential pitfall in scientific writing than writing in the humanities and other disciplines. This is because scientific writing does not allow direct quotes from reference material. Everything must be paraphrased. This means that there is no margin for error in scientific writing.

      When most students think of plagiarism, they think of the most blatant cases, cases in which someone downloads an article from the web or buys a pre-written essay from an online service and presents it as their own. These are very serious offenses and they do occur. Usually it is not difficult to detect when this has been done. Students at the W have been caught doing this and they were expelled from the university.

      These blatant cases, however, are relatively rare. The most common form of plagiarism, both at the W and at universities across the country, is what we might call inadvertent plagiarism. These are cases where the student plagiarizes but the student is not entirely aware that what they have done is plagiarism. Often students doing this have some inkling they are skirting on the edge of propriety, but they convince themselves they haven't really crossed the line because they don't know how to do a better job. This kind of inadvertent plagiarism is most often due to the student's lack of experience in scientific writing and their lack of clear understanding as to what exactly does and does not constitute plagiarism.

      In a typical case, the student plagiarizes from a large number of sources. The student has done a significant amount of research and has taken notes from a nicely diverse group of books and articles. But when it comes time to write their essay or assignment, large numbers of the phrases come directly from the sources the student has consulted. The student doesn't recreate just a single source word-for-word, as they would in a case of blatant plagiarism; instead the student is trying to do the right thing by using information from a variety of sources. Unfortunately, in the end, the essay or assignment contains strings of phrases taken directly from the sources used — a phrase from one source, followed by another phrase from a second source, followed by a phrase taken from a third source, etc. In many cases, the student will scrupulously cite all the sources for their phrases. The student is not really intending to plagiarize and is trying to follow acceptable writing and citing procedure. But, if the phrases closely resemble (they don't even have to be identical) those of the original source, it is still considered a form of plagiarism, even if the sources have been cited! The penalties for plagiarism still apply, even if it was inadvertent plagiarism.

      Good intentions are not enough to avoid charges of plagiarism and the subsequent penalties. All that matters is the final result. It must be free of all forms of plagiarism, blatant or inadvertent.

      The student cannot resort to the expedient of just putting quotes around the phrases taken from their sources, because direct quotes are generally not allowed or used in scientific writing. There are exceptions. For instance, in Dr. Oppenheimer's MA 111/112 writing assignments, direct quotes are permitted with proper citations. However, unless you are explicitly told otherwise by the instructor, assume that direct quotes are not permitted in any science or math writing you are assigned.  


2. Specific examples of plagiarism.

In scientific writing, you generally don't plagiarize information (especially if you have cited the source), you plagiarize how that information is presented. Here, with examples, are some of the ways students commonly plagiarize scientific writing. All the examples will use as their starting point the same text:

By lining up chimp chromosome 22 and human chromosome 21 and comparing them nucleotide by nucleotide, the consortium found instances in which one nucleotide was substituted for another in only about 1.44% of the sequence. The chimpanzee chromosome has been sequenced to an accuracy of less than one error in 104 bases, so sequencing mistakes account for less than 1% of the observed single-nucleotide mismatches. There is also an impressive number (68,000) of small to large stretches of DNA that have been either gained or lost (these are called insertions or deletions, indels for short) in one species or the other.

Source: J. Weissenbach. 2004. Nature vol. 429 27 May 2004, pp 353-355.


Example 1 - Complete plagiarism despite citation

Comparing the genomes of humans to chimpanzees has yielded key insights into the evolutionary relationships between the two species. Some of these insights come from aligning individual chromosomes from the two species and looking for both similarities and differences. For instance, when the sequence of chimp chromosome 22 is compared to its human counterpart more than 98.5% of the sequence is chimp chromosome has been conserved in its human counterpart, but differences at the nucleotide level do exist.  The chimpanzee chromosome has been sequenced to an accuracy of less than one error in 104 bases, so sequencing mistakes account for less than 1% of the observed single-nucleotide mismatches (Weissenbach, 2004.) One of the ultimate goals of these comparison efforts is to determine which of the sequence differences between chimps and humans account for their different traits.

NOTE: Copying even a single sentence word-for-word is considered plagiarism even if the surrounding sentences are different and even if the copied sentence cites the source.


Example 2 - Still plagiarism despite changing a few words

Comparing the genomes of humans to chimpanzees has yielded key insights into the evolutionary relationships between the two species. Some of these insights come from aligning individual chromosomes from the two species and looking for both similarities and differences. For instance, when the sequence of chimp chromosome 22 is compared to its human counterpart more than 98.5% of the sequence is chimp chromosome has been conserved in its human counterpart, but differences at the nucleotide level do exist. The chimpanzee chromosome has been sequenced with an error rate of less than one error in 104 bases, so errors in the actual sequence-gathering process account for less than 1% of the observed single-nucleotide mismatches (Weissenbach, 2004.) One of the ultimate goals of these comparison efforts is to determine which of the sequence differences between chimps and humans account for their different traits.

NOTE: Taking the author's original sentence and changing a few words but leaving large parts of the original sentence's words and structure intact is still considered plagiarism, even if the slightly re-written sentence cites the source.


Example 3 - Avoiding plagiarism

Comparing the genomes of humans to chimpanzees has yielded key insights into the evolutionary relationships between the two species. Some of these insights come from aligning individual chromosomes from the two species and looking for both similarities and differences. For instance, when the sequence of chimp chromosome 22 is compared to its human counterpart more than 98.5% of the sequence is chimp chromosome has been conserved in its human counterpart, but differences at the nucleotide level do exist.
Chromosome 22 of the chimpanzee has had its sequence determined with an error rate lower than one in 10,000 nucleotides, so errors in the actual sequence-gathering process are responsible for no more than 1% of the individual nucleotide differences that have been found between humans and chimps. (Weissenbach, 2004.) One of the ultimate goals of these comparison efforts is to determine which of the sequence differences between chimps and humans account for their different traits.

All the words from the original sentence have been changed. However, it is true that the essential structure of the sentence – what information is presented in what order – has been retained. This is not a problem as long as you are limiting the structural similarities to one sentence. If there were many sentences in a row taken from an original source, with their wording changed but the essential sentence structure unaltered, you are in danger of committing structural plagiarism (which we will define below) despite the efforts to reword the material.



In the first two examples, the writer is guilty of some degree of plagiarism because they have relied on the original author to express the ideas for them.

In the case of students writing essays, reports, and assignments for class, two of the most important things the instructor is looking to grade the student on are:

  1. Did the student do a good job researching the topic; and
  2. Was the student able to show an understanding of the details of the topic?

If the student has constructed a piece of writing by pasting in other authors' sentences with appropriate citations, the student is demonstrating that they successfully accomplished 1. They did a good job of researching the topic and finding information from a variety of (cited) sources.

But the student is not demonstrating 2, an understanding of the material, and the student's mark will suffer accordingly. Unless the student puts the information from their sources in their own words, the instructor has no way of knowing if the student really understood what they were reading. All the writing demonstrates is that the original authors understood the topic. Did the student understand the topic? The instructor can't tell one way or another.

If you understand a topic, you are able to articulate your understanding in your own words. You need to do this in your writing if you want full marks and if you want to avoid charges of plagiarism.


3. What are the penalties for plagiarism at The W?

At the W, any work an instructor has deemed to be plagiarism is given an automatic zero by university policy. In addition the student's Dept Chair, Dean, and the Vice President for Academic Affairs' office is notified of the offence. The Vice President for Academic Affairs (VPAA) keeps a file on all students who have committed acts of academic dishonesty, including acts of plagiarism.

If the plagiarism is a first offence, the matter is noted in the student's file and no further action is taken. If there are previous offences of any kind that have occurred during the student's time at the W (they need not have occurred in the same class, the same semester, or same year), the student must appear before the university's Academic Standards Committee. The committee has the power to impose additional punishments on the students beyond those already imposed by the instructor(s) who first reported the academic dishonesty. These additional punishments can include failing the course, suspension, or expulsion from the university. The committee is not required to impose these additional punishments – they can choose to do nothing beyond what the instructor deemed appropriate – but they do have the power if they feel the case warrants them.

More ambiguous acts of plagiarism, that might arise out of a misunderstanding of what exactly constitutes plagiarism (for instance, copying a sentence word-for-word, but then citing its source) might be met with less severe penalties, at least on the first offense. Or they might be punished equally harshly. It is up to the Committee. Of course, repeated offenses of even the most borderline cases of plagiarism will be met with increasingly harsh punishments. You can only claim ignorance for so long.

If a particular first act of academic dishonesty is considered sufficiently blatant and egregious, the VPAA can convene the Committee without waiting for a second offense.

You can read The W policy on plagiarism here.



4. How do you avoid even inadvertent plagiarism?

Here is an excerpt from Voet & Voet, 2004. Biochemistry 3rd Ed. John Wiley & Sons, Inc. p 35. It is titled, Reading A Research Article.

Research reports more or less all have the same five-part format. They usually have a short abstract or summary located before (or, in some journals, after) the main body of the paper. The paper then continues (or begins) with an introduction, which often contains a short synopsis of the field, the motivation for the research reported, and a preview of its conclusions. The next section contains a description of the methods used to obtain the experimental data. This is followed by a presentation of the results of the investigation. Finally, there is a discussion section wherein the conclusions of the investigation are set forth and placed in the context of other work in the field. Most of the articles are full papers, which may be tens of pages long. However, many journals also contain communications, which are usually only a page or two in length and are often published more quickly than are full papers.

It is by no means obvious how to read a scientific paper. Perhaps the worst way to do so is to read it from beginning to end as if it were some kind of a short story. In fact, most practicing scientists only occasionally read a research article in its entirety. It simply takes too long and is rarely productive. Rather, they scan selected parts of a paper and only dig deeper if it appears that to do so will be profitable. The following paragraph describes a reasonably efficient scheme for reading scientific papers. This should be an active process in which the reader is constantly evaluating what is being read and relating it to his/her previous knowledge. Moreover, the reader should maintain a healthy skepticism since there is a reasonable probability that any paper, particularly in its interpretation of experimental data and in its speculations, may be erroneous.

If the title of a paper indicates that it may be of interest, then this should be confirmed by a reading of its abstract. For many papers, even those containing useful information, it is unnecessary to read further. If you choose to continue, it is probably best to do so by scanning the introduction so as to obtain an overview of the work reported. At this point most experienced scientists scan the conclusions section of the paper to gain a better understanding of what was found. If further effort seems warranted, they scan the results section to ascertain whether the experimental data support the conclusions. The methods sections is usually not read in detail because it is often written in a condensed form that is only fully interpretable by an expert in the field. However, for such experts, the methods section may be the most valuable part of the paper. At this point, what to read next, if anything, is largely dictated by the remaining points of confusion. In many cases this confusion can only be eliminated by reading some of the references given in the paper. At any rate, unless you plan to repeat or extend some of the work described, it is rarely necessary to read an article in detail. To do so in a critical manner, you will find, takes several hours for a paper of even moderate size.

Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.

The following passage is what might result from an inexperienced researcher who writes while reading the original or who uses notes that copy out word-for-word large chunks of the original text. This passage is not taken verbatim from the original, but it is nonetheless an example of plagiarism. There are some phrases and word choices that were lifted from the original. These have been bolded in blue:

Articles from most biological journals typically follow a standard format. They are prefaced with an abstract summarizing the article. The article proper begins with an introduction giving the background information that lead to the current study. The introduction usually ends with a preview of the article's main conclusions. The introduction is followed by the methods section of the article. This is a detailed description of the methodology used to obtain the experimental data. Next comes the actual results and findings of the experiments are described. Finally, a discussion section reveals what the researchers have concluded from their studies and attempts to fit those conclusions in with other work in the field.

The worst way to attempt to read a journal article is from beginning to end. Instead, the reader should take a selective approach and dig deeply into the article only when it appears that meaningful information will result. The reader need only begin the article if it has an interesting title and abstract. Scanning the introduction will provide an overview of the workas a whole. Turning next to conclusions at the end of the discussion section will reveal what the researchers believe they actually found as a result of their work. If further information is desired, the results section can provide information about the experimental support for these conclusions. The methods section often does not need to be read except by experts interested in the picayune experimental details of the research. What remaining parts of the article need be read in any greater detail depends of what aspects of the preceding reading left questions in the reader's mind. Papers need be read in their detailed entirety only infrequently (Voet & Voet, 2004.)

There is a significant, but not overwhelming, number of word choices and phrases lifted from the original. But even if these were eliminated and other constructions were substituted, the passage as it stands would still constitute plagiarism. It is too close to the source to be considered an original work by the author. It makes all the same points in the same order using several of the same expressions and phrases. There is nothing in this passage that is not in the original.

Citing the source does not change this. Citing a source does not lift the obligation on a writer to produce original work.


A better strategy would be to take notes that are as skeletal and as schematic as possible.

  • Avoid words whenever possible in your notes and you run less risk of plagiarizing phrases and word choices from the original.

  • Avoid structuring your notes in a sequential manner and you run less risk of plagiarizing the structure of the original.

  • Group related material together in your notes regardless of how the material was sequenced in the original.

  • Break up the sequence as much as possible so you will have a hard time recreating the original's structure from the structure of your skeletal notes.

Skeletal, fragmented notes taken from the original passage might look like this:


Attempting to write a passage from skeletal notes such as these will avoid recreating the structure and reusing the phrases of the original, because neither of those things is present in your notes, and you won't remember the original structure or phrases when you finally sit down to write up your notes. These kinds of notes force you to create your own phrases and structure, because they don't provide the original as an irresistible model to follow.

The hardest thing to do when taking skeletal notes is to avoid recreating the structure of the original source. Everyone has the tendency to write down information in their notes in the order they encounter it. Then, when writing up your own essay, it becomes very easy to just re-write the information in your notes in the same order. Even if you've taken pains to put all the information in your own words, you have still recreated the structure of the original and you lay yourself open to charges of plagiarism.

When taking skeletal notes, try to get out of the habit of writing down on the page and putting your notes in the same order in which you encounter them. You can try dividing your paper into different sections and randomly choosing a different section on a completely different part of your page every time you write something new down. You can try rotating your paper in different random directions every time you have something new to write down. Just make an effort to scramble the order of the information so that when you write up your notes you are forced to come up with a new order and structure that doesn't plagiarise the original's.

Skeletal notes styles



5. Other plagiarism resources.

Other resources on plagiarism, how to recognize it, and how to avoid it are listed below:

  1. Simon Fraser University in Vancouver, B.C., has a useful web-based tutorial -- including quizzes -- on plagiarism, how to recognise it, and how to avoid it. 

  2. Princeton University has a web page that discusses in some detail the ins and outs of academic integrity. The entry page provides links to discussions of various aspects on academic integrity. The site has a specific discussion of plagiarism at

  3. The Chronicle of Higher Education published several articles in their 17 Dec 2004 issue on plagiarism and several specific plagiarism cases. A good place to start is their article titled Everybody's Talking About Plagiarism. The article provides links to their related articles. (Requires subscription to access.)

  4.  Georgetown University has a good discussion, with examples, of plagiarism.

  5. Dartmouth University has a detailed discussion of how and when to properly cite sources.

  6. If you google plagiarism these days, you will provided with literally hundreds of links to sites dealing with various aspects of the issue.



6. Real-world cases of plagiarism.

Plagiarism is not limited to students. Here are some links to articles describing various authors, academics, journalists, and scientists recently accused of plagiarism.

Dr. Matthew Whitaker, Associate Professor of History at Arizona State University, was accused in 2011 and again in 2015 of plagiarising the sources for books of popular history he had written. Dr. Whitaker had inserted paragraphs from his sources with only a few words changed, and even though he often, but not always, cited those sources, he was accused of taking the work of others. A side-by-side comparison of some of the material he had plagiarised is available here (limited free articles from the linked site; then a paywall applies.) Dr. Whitaker was asked to resign from all his positions at the University effective May 2017.

In July 2009, a published research article was retracted by the journal that published it because it contained two paragraphs plagiarised word-for-word from an earlier review article on the same topic, written by someone else. There were no complaints about the science in the paper, conducted by a research group lead by Professor Karim Nayernia at Newcastle University (Newcastle Upon Tyne, UK). The paper dealt with creating sperm cells from human embryonic stem cells and was originally published in the journal Stem Cells and Development. This was the first report of developing functional sperm cells from human stem cells and represents a significant development in stem cell technology, if the results hold up, but the editors at Stem Cells and Development considered the plagiarism in the introductory material transgression enough to retract the entire paper. Professor Nayernia claims he mistakenly sent the journal an early draft of the paper and that the final draft would have removed the plagiarism.

Fareed Zakaria is a journalist and pundit who has worked as a columnist for Newsweek and Time magazines and for the Washington Post, and who hosts a political discussion show on CNN. In 2012, Zakaria was accused of plagiarising a passage from Jill Lepore's New Yorker article on gun control for a Time magazine column on the same subject. Further investigation revealed multiple instances of inserting paragraphs from other people's works into his books and columns. Here is a side-by-side comparison of some of the passages Zakaria is accused of plagiarising. Zakaria did rephrase some of the passaages slightly, but the original's phrasing was usually left mostly intact. After the plagiarism was made public, Zakaria issued a statement apologising for the similarities and taking responsibility for what he termed his "terrible mistake". Zakaria was suspended by both Time magazine and by CNN for the incident. The suspensions lasted a few weeks each, but then Zakaria returned to his regular duties at both organizations. He still works for CNN, and now writes for the Washington Post.

Doris Kearns Goodwin is another well-respected and best-selling author of several books of popular history. Her books include Team of Rivals: The Political Genius of Abraham Lincoln (2005), The Fitzgeralds and The Kennedys (1987) and No Ordinary Time (1995), which won the Pulitzer Prize for non-fiction. In 2002, Goodwin was accused of using plagiarized material in many of her books. Here is summary of the charges against Goodwin and the controversy that followed them.

The author of The Da Vinci Code, Dan Brown, has been accused of plagiarizing ideas and structure from an early novel, The Da Vinci Legacy by Lewis Perdue. Perdue does not accuse Dan Brown of copying his words or sentences, but maintains the similarities in the plot points and structures of the two novel can legitimately be classified as plagiarism. Random House, the publisher of The Da Vinci Code, successfully sued Perdue to establish that Perdue had no legal basis for declaring Brown had plagiarized him. Perdue and others claim that the similarities might not fit the legal definition of plagiarism, but do fit the common-sense definition.

Kaavya Viswanathan was a Harvard University undergraduate who, when she was just 17 years old, was signed to a $500,000 contract to write two young-adult novels. Her first book was published in Spring 2006 and a Hollywood studio bought the rights to turn it into a movie. In April 2006 The Harvard Crimson published a story accusing Viswanathan of plagiarizing two books of another young-adult author, Megen F. McCarthy. Eventually, at least 14 passages similar in phrasing and structure to McCarthy's writing were discovered in Viswanathan's novel. Passages similar to works by other authors were also discovered. Wikipedia has the complete list of suspect passages. Viswanathan's novel was withdrawn by the publisher and the plans to make a movie version were halted. Despite the close similarities to other authors' works, Visawanathan said the copying was unintentional and unconscious. Harvard university declined to get involved in the case, saying the plagiarism was non-academic and is not covered by Harvard's code of conduct for students. She continued as a student there and graduated with honors in 2008. After Harvard, she entered law school at Georgetown University.

In March 2006, The Washington Post hired Ben Domenech as a blogger for Red America, an online offering from the paper. Three days after he was hired, Domenech had to resign amid accusations he had plagiarized other people's writing on at least 12 occasions while a student at The College of William and Mary.

Plagiarism of scientific articles is not all that common, but it does happen. Yung Park, a materials scientist at the University of Cambridge in England, is accused of copying other scientists' journal articles from 1997 to 2001 and submitting them as his own research. Park was asked to leave Cambridge. The journals which published his papers have added notes to their archives indicating that the papers contain plagiarized material and in some cases have entirely removed the articles from their archives.



Written by: Ross Whitwam

Last updated: 25 July 2021