To put your name on a piece of work is to say that it is yours, that the praise or criticism due to it is due to you. To put your name on a piece of work any part of which is not yours is plagiarism unless that piece is clearly marked and the work from which you have borrowed is fully identified. Plagiarism is a form of theft. Taking words, phrasing, sentence structure, or any other element of the expression of another person’s ideas, and using them as if they were yours, is like taking from that person a material possession, something that person has worked for and earned. Even worse is the appropriation of someone else’s ideas. "Ideas" mean everything from the definition or interpretation of a single word to the overall approach or argument. If you paraphrase, you merely translate from the person's language to yours; another person’s ideas in your language are still not your ideas. Paraphrase, therefore, without proper documentation, is theft, perhaps of the worst kind. Here, a person loses not a material possession, but something of what characterized the person as an individual.
If students wish to do one project for two courses or to draw on work previously done in order to complete an assignment for a current course, they must get the expressed permission of all affected faculty in advance of turning in the assignment. The faculty suggests that approved combined projects should represent significantly more effort than the individual projects they supplanted.
Plagiarism is a serious violation of another person’s rights, whether the material stolen is great or small; it is not a matter of degree or intent. You know how much you would have had to say without someone else’s help, and you know how much you have added on your own. Your responsibility, when you put your name on a piece of work, is simply to distinguish between what is yours and what is not, and to credit those who have in any way contributed.