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Research Guides

Citing Sources: Why are there so many citation styles?

An overview of tips, tools, and resources for all your citation needs

It can be frustrating to have to use different citation styles for different classes! But, there are reasons that different disciplines use different styles of citation. While there are dozens of different citation styles, all citations, regardless of style, will contain substantially the same bits of information about the source necessary for the reader to track it down. Differences in citation styles come down to formatting differences in the order of the information elements, capitalization, punctuation, and presentation of the author’s name, as well as how the individual references are presented within the text. Most citation styles can be broadly classified into two systems for referencing: 1) parenthetical (in-text) citations and 2) numbered citations.

Why use a parenthetical citation style?

  • MLA (author-page) referencing style emphasizes page numbers (or line numbers, sections, or other markers) rather than publication year in parenthetical references because these disciplines are often engaged in textual analysis or other forms of research that make heavy use of quotation and emphasize the researcher’s reading of a particular text and edition.
  • Harvard (author-date) referencing styles like APA, Chicago Author-Date, and CSE Name-Year are used in disciplines that place particular emphasis on the currency of information and/or examine the evolution of scholarly schools of thought.

Why use a numbered citation style?

  • Oxford (footnote/endnote) referencing styles like Chicago Notes are used in disciplines that make heavy use of sources for which citations don't fit neatly in a brief parenthetical reference such as government documents, legal cases, primary documents, and manuscripts.
  • Vancouver (numbered sequence) referencing styles like IEE, AMA, CSE Citation-Sequence,and CSE Citation-Name are used in disciplines that cite a high number of studies, in order to let the text be read more easily without long interruptions from a string of in-text parenthetical citations.

Pro Tip

Style manuals and guides dictate more than just in-text citation and reference list formatting.  They also have rules for how to structure your paper and, in some cases, the cover sheet for your paper.  Don't worry, each citation style has its own manual to help you figure out exactly how it all works. 

To find more information on specific citation styles and their corresponding style guide, check out the pages in the Citation Style Guides section.