The Catholic Distance University's Academic Conduct Policy defines plagiarism as:
... the act of using another person’s ideas or expressions in your writing without acknowledging the source…In short, to plagiarize is to give the impression that you have written or thought something that you have in fact borrowed from someone else…The most blatant form of plagiarism is to repeat as your own someone else’s sentences, more or less verbatim…Other forms of plagiarism include repeating someone else’s particularly apt phrase without appropriate acknowledgment, paraphrasing another person’s argument as your own, and presenting another’s line of thinking in the development of an idea as though it were your own. (Joseph Gibaldi and Walter S. Acthlert, MLA Handbook for Writers of Research Papers (New York, NY: Modern Language Association of America, 1984)