Doyle Online Writing Lab

Plagiarism, Citation and Style Guides

When to Cite a Source

When do you need to cite a source for information?

  1. Quotations.
  2. Paraphrased information. Please note that you need to actually put it in your own words. If it is too similar to the original it is still plagiarism, even if you cite your source.
  3. Information learned in lecture, in course readings, or in class. An idea presented in Hum 110 lecture, for example, needs to be cited. See the below citation formats for more about just how to cite these types of sources.
  4. Facts that aren't common knowledge. Common knowledge is often defined as what the average U.S. citizen (think high school senior) would know without having to look it up. For example, it is common knowledge that there are 24 hours in the day, or that New York is both a city and a state. In general it is better to error on the side of overcitation: if you had to look it up or didn't know it before you read a certain work, cite your source.

Citing a source means giving the author and page number either parenthetically or in an endnote/footnote. In addition, one must include the full reference somewhere in your work. This can occur in a bibliography or works cited, or in the first footnote or endnote that refers to that work. Please see below for when to use what kind of citation.


Plagiarism is not always as black and white as it might seem.  When in doubt, consult with your professor.  The following websites provide a good overview of the "grey areas" that surround this issue.

Citation Formats

Disciplinary Preferences

Different citation formats are popular with different academic disciplines. Generally the forms preferred for the various disciplines are as follows:

  • MLA (Modern Language Association) style (parenthetical notes): English, Foreign Languages, Linguistics.
  • University of Chicago style (footnotes): Greek, Latin, and Ancient Mediterranean Studies, Dance, Folklore, History, Music, Theatre.

Parenthetical Footnotes

When a professor asks you to include "parenthetical footnotes" he means that instead of placing the footnotes at the bottom of the page you are to place them in parentheses within the body of the text where you would normally type the note number. It is usually a good idea to use parenthetical notes for works that you site a great deal in the course of your paper (i.e., if you were writing a paper on Madame Bovary you might want to cite that primary text parenthetically). Parenthetical notes can take any number of forms: (1) they can be traditional footnote citations (above) differing only in their placement (2) they can be abbreviated, sometimes offering only the author's last name and the page number of the cited passage, or (3) they can be abbreviated to the extent of offering page numbers alone (this should only be done with ONE source in a paper).

It is generally a good idea to just ask your professor to specify which form of citation she prefers.

Citation Styles

Reed College LibGuides

Style guides and manuals

Elements of Style (Strunk and White)

"Politics and the English Language" by George Orwell (a clever piece on writing good prose)

Chicago Manual of Style Notes and Bibliography Guide 

MLA Style Guide overview (adapted from Purdue OWL website)