

Note: Some works written with MLA or APA style also include what are called discursive footnotes. See Signaling Sources in the Body of Your Paper for more information. All three of these styles have different conventions for how to refer to a source in the body of your paper. Please see More Notes on Chicago Style Footnotes for more information about how Chicago style is treated in this guide. Chicago style is more flexible than MLA and APA formats, and therefore more complicated to explain. The footnotes can be consulted if someone wants to track down your source for further research. When developing a historical explanation from multiple primary sources, using footnotes instead of inserting parenthetical information allows the reader to focus on the evidence instead of being distracted by the publication information about that evidence. Chicago style is especially popular in historical research.

The footnote style we demonstrate here is called Chicago style, defined by the University of Chicago.

The alternative to in-text citation is to use footnotes, which give source information at the bottom of the page. Although the author’s name is an important element in APA citations, this style emphasizes the year the source was published, rather than the page number, which allows a reader to see quickly how the research you’re writing about has evolved over time. (2) APA style, defined by the American Psychological Association, is most common in the social sciences. This information allows scholars to track down easily the exact sentences you’re analyzing. Because humanities research highlights how one piece of writing influences another, MLA style emphasizes the author’s name and the page in the original text you’re using. (1) MLA style, defined by the Modern Language Association, is most common in the humanities. The first two styles are known as “in-text” citation styles, which means that you give some information about the source directly after the quotation, but leave the rest to a list of References (APA) or Works Cited (MLA) at the end of the paper. All three of these styles require the same basic information, but the order of that information varies, in part because different academic fields emphasize different elements of a source when referring to previous research. This guide covers the three main styles used at Yale. In some instances, even two journals in the same field will use different styles.

Academic disciplines have varying expectations for how to list citation information.
