There has been plenty of discussion on the basic issue of students self-plagiarizing from one course to another as well as academics self-plagiarizing prior but unpublished material in a later publication, but I was thinking of something slightly different that I haven't seen discussed.
Is it plagiarism for a student to submit material that was written prior to the course start date or otherwise outside of the supervision of the instructor as long as the material was written outside the aegis of academia? Most self-plagiarism policies that I've seen, such as Harvard's, mention that the prior work must have been submitted to another course for it to constitute self-plagiarism.
If doing something like that would be ethical, would any of the following further situations be ethical?
1) Submitting prior material that was prepared for a prior class but never submitted/turned in. This could be because the student withdrew from the course before submission, the student was expelled before submission, or the student decided to start over from scratch on the assignment. For example, a student writes a paper on Mary Shelley for his Survey of British Literature course, but then decides that he really would rather do a paper on Jane Austen and writes one on her and turns it in instead. Later, the student finds himself enrolled in Introduction to Science Fiction and finds himself without a lot of time. Is it ethical for him to patch up his never submitted Mary Shelley paper (e.g. with corresponding corrections to make it meet the expectations of the new course) and turn it in?
2) Submitting prior material that was completed and submitted for a course that the student took an an unaccredited university (or a university whose accreditation is not recognized by the student's current institution as legitimate). Since an unaccredited university is, for most intents and purposes in academia, academically equivalent to no university at all (degrees and credits are not recognized, etc.), this would seem to be ethically equivalent to submitting material completed under the supervision of a private tutor.
In the first case you mentioned, submitting work you have never previously submitted, that is absolutely ok.
In the second case, even if an institution is non-accredited, technically you still submitted the work to be graded, which is tantamount to "publishing" it. Whether you would get caught depends on whether that non-accredited institution submitted your work into the universal database (Turnitin or whatever).