Plagiarism—presenting someone else’s work as your own—rears its ugly head in many forms. Everyone knows that paying someone to write your college application essay is illegal; everyone knows that copying an online article on The Scarlet Letter is unethical. And most people realize that lifting a sentence or two verbatim from a couple of different encyclopedias and stringing them together is extremely fishy.

But plagiarism also includes taking credit for other people’s ideas, not just their words. Say you are poking around online, doing research for a paper on Hemingway and nature. You find an article that makes a great point about rabbits in For Whom the Bell Tolls—great because it’s useful for your argument. The text reads:

You rejoice and triumphantly type into your document, “The rabbits in For Whom the Bell Tolls are vulnerable natural creatures, much like Robert Jordan and his friends.” Uh-oh. Although the only important word you’ve copied is vulnerable, the main idea in your sentence is the comparison between Robert Jordan and the rabbits, and this comparison is not yours. It comes directly from the article you found online. Unless you give the writer credit for the idea, you’ll be committing plagiarism. For more on how to give credit where credit is due, see Footnotes and Endnotes and Citations in Text.