As I have been reminding people recently I both maintain a plagiarism Web site and teach the occasional linguistics course. This is one of those times I’m glad to see an issue like plagiarism from multiple points of view.
Interestingly after teaching a few times, I have decided that the real solution isn’t last-minute comparisons, but frequent interaction. So my tips, such as they are, include
Frequent assignments – It is true that the more you see a student’s work, the more likely you will spot an anomoly. In fact, blogging is one of the better tools because students really write in their own voices, and instructors see them, but may not have to grade the content in too much detail.
I know this assumes a reasonably low student:faculty ratio which does not always happen here. Even so, I have been in a class of 50+ where plagiarism was detected – Overworked TAs can smell a rat even in a large data set.
The early scare – Like John Harwood and others, I include a statement in the syllabus discuss the issue in the first day of class. The ultimate weapon of course is “I maintain the plagiarism site.”
Laying out collaboration rules – The great thing about collaboration is that students can learn from each other, but the bad thing is that they can get lazy also. My own personal rule has been “use your own words” (so that each student has to process some information). If nothing else, I learn who is studying together up front…in case anything weird happens later.
I think the ultimate lesson for me though is that plagiarism really may not pay for the student, even in the short term.
For instance, I questioned a student about copying a transcription from second student, but even if I hadn’t caught it, that person would have scored worse…because the two dialects did not mesh. The original transcription was correct for the original speaker’s dialect, but wrong for the other person. I knew that the student with the suspicious case totally missed the concept.
Another interesting case was a paper in which significant portions were cut and pasted from another source; I scored it as “missing quotations” since the reference was in the bibliography. Even if I had missed that one though – the paper would have scored low because the source materials were not meshed in well and was ultimately not very comprehensible.
I suspect I have been hosed a few times (for instance, there will be no more bathroom breaks for in-class exams), but overall I feel that I can worry less, because the results of plagiarism are amazingly shoddy in many cases.