I have a little more to say about the anti-PDS arguments. They don't address the underlying principles thoroughly enough, in my opinion. That is to say, the anti-PDS arguments don't provide any specific and practical alternatives. The CCCC-IP statement does recommend that if faculty members or institutions are going to use PDS, they should provide an opt-out clause for students, but they don't say what that opt-out clause would entail, or why. A good anti-PDS argument, one that one be more persuasive to me, anyway, would address the following questions:
Are all plagiarism detection methods undesirable? If not, which ones are acceptable, and why are some preferable to others? I remember back in the day when I was in high school and college (late 1980s, early 1990s), we didn't have the internet (most didn't, I mean), but that didn't stop people from plagiarizing. Professors detected it by intuition, and they called students into their offices to interview them about it. They might, for example, ask students to bring in all their sources and notes. This invariably caused great vengeance and furrrrious anger among students, especially those who had not, in fact, plagiarized (this happened to friends of mine). Some professors required that we turn in our "paper trails" along with our research papers -- every single source, notecard, note written a cocktail napkin or brown paper sack, etc. I was only too happy to do this; I was proud of having done every bit of that work myself, and I wanted the professor to be able to see it.
The internet made it easier to plagiarize, and it also made it easier for professors to prove instances of plagiarism. Obviously a professor feels less accusatory asking a student into his or her office to discuss a possible plagiarism case if he or she has the verbatim source in hand. The downside (or upshot, depending on your personal teaching philosophy) of this was that the burden of proof essentially shifted from the student to the instructor.
Okay, so back to my question. In my discussions with opponents of PDS, it's unclear that any methods of plagiarism detection at all are acceptable. Too much zeal to trust students can lead to a tacit "look the other way" practice which is naive, irresponsible, and just as likely to breed resentment among students who do the writing as PDS do. The alternative offered is something along the lines of "start a dialogue with students about authorship and intellectual property." "Require students to submit multiple drafts and monitor the writing process closely." "Talk to students about the importance of speaking for oneself and what a meaningful act that is. Frame it in such a way that shows that copying a paper from the internet is basically letting someone else speak for you."
Fair enough, those are all valid practices. But professors who do those things can end up with plagiarism cases in spite of all of it. What exactly do you do at the moment of encounter with that paper that you're 99.9% sure is plagiarized? Assuming you should try to verify this, how should you do so? Please know that I'm not trying to set up a false dilemma or slippery slope. I realize that "use Turnitin or do nothing" are not our only choices. What I'm pushing for is a clear alternative: a set of specific recommendations, each with a rationale.
1. Googling passages from the paper;
2. Calling a student into the office (without attempting to get any proof in advance);
3. Requiring a paper trail along with the submission of the paper;
4. Having students interview each other during peer review about the ethical use of sources and then preparing an "originality report" like Turnitin does as part of the peer review;
5. Having students submit multiple drafts;
all are plagiarism detection methods. What's the difference between these and Turnitin? The boldfaced difference is that Turnitin makes money and the others don't.
Googling passages from the paper would probably meet the criterion of "does not foster a 'guilty until proven innocent' culture," if you don't google passages from everyone's papers, only those that are suspicious for whatever reason (see my last post).
Calling a student into the office can arouse immense hostility and rage, one of the arguments against Turnitin. [Edited to clarify: Calling a student into the office without any proof can make a student angry, perhaps especially if the student didn't plagiarize, and this anger can spread to the entire class. This compromises the desired supportive, friendly, trusting teacher-student relationship that is conducive to developing student writing.]
Requiring a paper trail with the paper is similar to Turnitin in that everyone has to submit to it, again the "guilty until proven innocent" argument.
Having students interview each other during peer review and prepare originality reports for each other is something that, I'll admit, just popped into my head as I was trying to think of all the possible ways to detect plagiarism. Again, though, if everyone has to do it, it too does not meet the "does not foster a 'guilty until proven innocent' culture" criterion. But someone should try it and let me know how it goes.
Having students submit multiple drafts, thereby allowing the instructor to micromanage the writing process and give the maximum amount of guidance and feedback, is good in a lot of ways, but in order to be a way to detect plagiarism, there has to be some source or set of sources to compare the drafts to, so I'm not convinced that it's all that effective as a plagiarism detection method. Plus, one could write a draft, revise it a few times, then for the final draft, add a big chunk of text from a web site. Then what do you do?
I just want to see all the options clearly parsed out and considered from all angles. Maybe there are lots of people whose only beef with Turnitin is the fact that they make money and who would argue that any other plagiarism detection method, provided it doesn't make money, is fine. If that's the case, I'd like CCCC-IP to say so.