Quoting, summarizing and paraphrasing all use someone else’s work. Plagiarism is using another person’s words or ideas without giving them credit, whether on purpose or by accident.
| You use | Quotation marks? | Citation? |
|---|---|---|
| Their exact words | Yes | Yes |
| A paraphrase of their passage | No | Yes |
| A summary of their work | No | Yes |
| Their idea, data, chart or image | No | Yes |
| Common knowledge | No | Usually no |
| Your own ideas and experiences | No | No |
Key idea
Put a source’s exact words in quotation marks, and cite anything you quote, paraphrase or summarize, including ideas, numbers and images. Common knowledge needs no citation. When in doubt, cite.
Why it works
Citations do three jobs: they give credit to the people whose work you used, they let your reader check and follow up, and they show which ideas are yours. Purdue OWL describes common knowledge as information a reader can find in many credible sources (it suggests about five as a rough guide), and its golden rule is “When in doubt, just cite.”
Worked example: Common knowledge or not?
Does “George Washington was the first president of the United States” need a citation? Does “About one in four teens in the survey reported fewer than six hours of sleep”?
- The first is in countless reliable sources and known to most readers: common knowledge.
- The second is a specific finding from one survey: someone did the work to find it.
Answer: The first, no. The second, yes.
Worked example: A paraphrase needs credit too
Lucas rewrites a paragraph from a website entirely in his own words and leaves out the source. Is that plagiarism?
- The words are his, but the ideas came from the website.
- Ideas need credit as well as words.
Answer: Yes. A paraphrase still needs a citation.
Common mistake
Thinking a citation is needed only for direct quotations, or that facts everyone knows need one. Ideas, paraphrases, summaries, numbers and images all need credit; common knowledge doesn’t. Check: did I learn this from a particular source while working on this paper? If yes, cite it.
Accidental plagiarism usually starts with careless notes. When you take notes, put copied words in quotation marks and write the source and page beside every note, so you always know what is yours.