Two major approaches have been taken to detecting plagiarism: One is the use of plagiarism detection programs such as Turnitin. https://www.turnitin.com/
Sources
- University Policy for Using Online Plagiarism Detection Tools
Carnegie Mellon University Eberly Center for Teaching Excellence and Educational Innovation - Making Sense of Turnitin Reports
Yale University Poorvu Center for Teaching and Learning
There has, however, been criticism of this approach, and it can be controversial.
It is also possible to do a Google search on a specific group of words or a phrase that is common in the document you are checking to determine whether the search identifies sources in which these words have been used.
Signs of Possible Plagiarism
The other approach is to learn to identify the signs of plagiarism in student writing. These include lack of references or citations, citations of outdated or obscure sources, inconsistent formatting or margins and fonts, abrupt changes in tone or tense, vocabulary or word usage that is out of character for the student writer, and papers that are slightly off topic or do not follow instructions. These sites present some specific ideas:
- Signs Denoting Possible Plagiarism
Washington State University Libraries - How to Prevent Plagiarism in the Classroom: A Guide
American University School of Education - Resources for Teachers: How to Detect Plagiarism
Massachusetts Institute of Technology Writing - Discouraging and Detecting Plagiarism
University of Illinois Center for Innovation in Teaching and Learning