Many people at the university use a service called "TurnItIn" for submitting student papers. TurnItIn scans the student papers and compares them to a large database of student papers, web sites, and published documents to detect possible plagiarism. However TurnItIn is a paid service that the university has periodically cancelled during tough budgeting times.
There is another site that offers a similar service, for free. "Doc Cop" allows you to submit all your student papers together, and will compare the papers to each other. This is a much more limited comparison and will only detect the possibility of students copying from each other. However if you include the text of articles or other sources that you believe students may have copied from in the documents that you submit, you can extend Doc Cop's scanning abilities somewhat.
These types of tools should be used with caution. It is important to recognize that the tools often cannot differentiate between properly referenced quotations and outright plagiarism, so they only report a probability of plagiarism. Furthermore, while they can be an effective deterrent, they can also set a tone that suggests plagiarism is OK as long as it cannot be detected, when the ideal that you want to instill in your students is that they will benefit by doing their own work - the negative versus positive atmosphere can make a telling difference in your classroom and in the students' education.
For more information about TurnItIn, contact the Division of Continuous Education and Outreach, http://ce1766.rutgers.edu/.
Doc Cop is available for free at http://www.doccop.com/ (some extended services require payment).
CTAAR maintains a list of additional resources for our Detecting Plagiarism and Cheating workshop.
