Skip to Main Content

BIOL Course Guide: Citing

Why Cite?

When you quote or paraphrase the idea of another person in your research paper or speech, you must provide a proper citation for the source. These citations:

  • give credit to the author
  • enable others to locate the source that you cited
  • improve the credibility of your work, especially if you cited authoritative sources

If you use other people's words, ideas, or work (including graphics, charts, and tables) without properly giving them credit, you are committing plagiarism.

There are many forms of plagiarism, which include, but are not limited to:

  • Not properly citing your sources when paraphrasing or quoting
  • Re-using your own class paper/assignment in other classes (self-plagiarism)
  • Copy-and-pasting from another paper, website, or article 
  • Buying, selling, or submitting a paper written by someone else as your own

Use the chart below to help you determine when something should be cited. 

If it is... Should I cite?
someone else's words Yes, cite it as a quote 
someone else’s idea or theory but in my own words Yes, cite it as paraphrased
my own idea or experience  No need to cite
common knowledge  No need to cite

Hint: You can usually regard information and facts as common knowledge if you can find that same information in at least five credible sources without it being cited. However, when in doubt, cite it!

Paraphrasing

Be careful when paraphrasing information into your own words. Simply swapping out some words with synonyms is not proper paraphrasing. You must critically analyze and interpret the original passage and restate the essential points entirely in your own words. For more tips about paraphrasing, visit the Purdue Online Writing Lab (OWL).

Plagiarism Scale

Citation Styles

The format of a proper citation depends upon the citation style being used.  Most commonly, students are required to use APA or MLA.  
For consistency, both of these styles provide specific standards for:

  • citing within the body of a paper (in text)

  • a bibliography or reference list at the end of a paper

How to Know When to Cite:

When to Cite

graphic depicting when to cite