Ethical research: Avoiding plagiarism & learning when to cite

The following material is reproduced, with permission, from Yale University’s Centre for Teaching & Learning. You can follow that up through this link: Yale: When You Must Cite.

As it says there:

Although you should use sources creatively and flexibly to help you generate ideas and sharpen your argument, there are some hard-and-fast rules about the way sources should be acknowledged in your project. Click on the links for more explanation of the various rules.


ALWAYS CITE, in the following cases:

  1. When you quote two or more words verbatim, or even one word if it is used in a way that is unique to the source.

  2. When you introduce facts that you have found in a source.

  3. When you paraphrase or summarize ideas, interpretations, or conclusions that you find in a source. For more explanation, see the Yale site Fair Paraphrase.

  4. When you introduce information that is not common knowledge or that may be considered common knowledge in your field, but the reader may not know it. For more information, see the Yale site Common Knowledge.

  5. When you borrow the plan or structure of a larger section of a source’s argument (for example, using a theory from a source and analyzing the same three case studies that the source uses).

  6. When you build on another’s method found either in a source or from collaborative work in a lab.

  7. When you build on another’s program in writing computer code or on a not-commonly-known algorithm.

  8. When you collaborate with others in producing knowledge.

These situations are explained below.


Always Cite:

  1. When you quote two or more words verbatim, or even one word if it is used in a way that is unique to the source.

    Most writers realize that they must acknowledge a source when quoting a memorable phrase or sentence.

    • They’d be sure to credit Mark Twain when quoting: “The coldest winter I ever spent was a summer in San Francisco.”

    • And you probably also understand that you do not need to cite words that are very common to your topic. When writing about Hamlet, you do not need to put the words “Hamlet” or “Shakespeare” in quotation marks, or cite a source for them, even though you may have read sources that use these words.

    • But when a single word or two are used in a distinctive way, so that the author is creating a new concept or applying it to a new topic, you must give acknowledge the source. When John Baker redefines the significance of the mirror test by saying that chimpanzees’ awareness of their reflection is not full consciousness, but a limited “kinesthetic self-concept,” it’s clear that those two words, as specialized terms of art, should appear in quotation marks in your paper. Even though neither “kinesthetic” nor “self-concept” is unusual on its own, as a phrase they belong to the author.

    • But even a single, non-specialist term—such as “consilience”—may become tied to an author (in this case, E.O. Wilson) through an influential publication, in which case you should put the single word in quotation marks, at least in your first mention of it in your text.

  2. When you introduce facts that you have found in a source.

    Facts that are generally accessible (the date of the Declaration of Independence, for instance) need not be cited to a particular source, but once you go up one level of detail on the information ladder, you probably need to cite the source (the number of people who signed the Declaration, for instance). And note that commonly known facts found in a particular or unusual context should be cited, so that the reader knows how your argument may have been influenced by the context in which you found it. For more, see below or follow this link to the Yale site Common Knowledge.

  3. When you paraphrase or summarize ideas, interpretations, or conclusions that you find in a source. For more explanation, follow this link to the Yale site Fair Paraphrase.

  4. When you introduce information that is not common knowledge or that may be considered common knowledge in your field, but the reader may not know it. For more information, follow this link to the Yale site Common Knowledge.

  5. When you borrow the plan or structure of a larger section of a source’s argument (for example, using a theory from a source and analyzing the same three case studies that the source uses).

    You may not be used to thinking of the plan of a source as proprietary to its author, but if you follow a source’s plan too closely without acknowledging that you saw it there first, you’re presenting as your own an analysis that someone else shaped.

    • For example, if you use Mark Hauser’s discussion of primates’ knowledge of other minds from Wild Minds and you discuss the same three experiments that he analyzes, then you must acknowledge this debt.

    • The simplest way to do this is to say “Like Mark Hauser, I find the three experiments carried out by X, Y, and Z groups to be useful in considering the extent of chimpanzee awareness.”

    An even better way—because it highlights your distinctiveness as a writer—is to distinguish the different use to which you will put the analysis.

    • If, for instance, you’re focusing on primate social skills rather than strictly on their awareness of other minds, you might write: “Mark Hauser examines three experiments carried out by X, Y, and Z for what they can tell us about knowledge of other minds. For my purposes, though, these same experiments shed important light on the social capacities of primates.”

    • These statements can come in a discursive footnote or in the main body, although if the statement distinguishes your argument from the source’s, it has an important role in the body of the argument.

    See Gordon Harvey, Writing With Sources, Chapter 3, for an excellent discussion of unfair borrowing of another’s plan.

  6. When you build on another’s method found either in a source or from collaborative work in a lab.

    Relying on someone’s research method is like #5 above—borrowing a text’s plan or structure.

    • If your approach to a problem is inspired by someone else’s work on a similar or analogous case, credit the original researcher.

    • Building on the work of others is appropriate and desirable, but methods, like specific words and phrases, are a form of intellectual property.

  7. When you build on another’s program or on a not-commonly-known algorithm in writing computer code.

    Although writing code may seem different from writing papers, the same standards of acknowledgment apply. If you rely on someone else’s program, you must credit that person. Some software algorithms are so well known that they rise to the level of Common Knowledge. Programmers use such pieces of code without acknowledgment. But if the code is not well known, someone reading your program might think you’ve authored parts that are borrowed. For a useful example of unauthorized code borrowing, read this paper that is located on your Moodle site

  8. When you collaborate with others in producing knowledge.

    You may sometimes co-author a paper or other text during college; these opportunities are often more frequent in the professional world.

    • When two or more people all contribute substantially to a piece, they normally list all their names as authors.

    But there are also occasions when someone gives help that does not rise to the level of co-authorship.

    • If you work with a lab partner to set up an experiment, for instance, but run and analyze the results yourself, you should credit the lab partner in a footnote or by reference within your paper.

    • Similarly, if you and a partner present a scene from a play, and you later write a paper using some insights you gained during production, you should credit the other actor.

    University life is structured so that your ideas will receive constant testing and refinement in discussion with others. You do not need to cite in your papers every conversation you have about the ideas or evidence. But you do need to develop a judgement about which conversations are incidental and which result in ideas that merit reference in your texts.

    If you take this warning as an opportunity, and make an effort to reveal the trail of your thinking in footnotes and acknowledgements, you’ll soon develop a sense of how to credit collaboration appropriately.