I'm having an interesting go round with a law review on the question of self-plagiarism. The article in question is yet another in my interminable series on director primacy. There's a section in the new article that summarizes the director primacy model which pretty closely tracks an earlier article's summary of the model. Candidly, there was more than a little cutting and pasting. The question is whether the material should be treated as a quotation or not.
Over at Crooked Timber, John Quiggin had an interesting discussion of this very issue a couple o years ago, with links to other discussions. Some folks are out to stomp out any self-repetition:
It is our belief that self-plagiarism is detrimental to scientific progress and bad for our academic community. Flooding conferences and journals with near-identical papers makes searching for information relevant to a particular topic harder than it has to be. It also rewards those authors who are able to break down their results into overlapping least-publishable-units over those who publish each result only once. Finally, whenever a self-plagiarized paper is allowed to be published, another, more deserving paper, is not.
In contrast, John draws a distinction that I think makes good sense:
I’ve seen quite a few cases where the same author has two papers that differ by one global Find and Replace, plus a corresponding adjustment in the notation.
At the same time, I don’t think this issue can be understood simply in terms of matching blocks of text. If, for example, Professor X writes ten papers on Problem Y, the summary of the literature and the description of the problem are going to be pretty much the same each time, even if there’s a substantial new contribution in each paper. Insisting that these pieces of necessary boilerplate be rewritten for each new paper seems rather pointless, and the alternative of citing or quoting the first paper for such material is silly.
In my view, that's exactly right. If the new paper simply restates the old paper, there's a problem. If the passage in question is the sort of boilerplate of which John speaks, and the new paper makes a new contribution to the literature, however, I don't see why a little repetition should be a problem (other than the possible risk of boring to death the reader who has seen it all before). Indeed, one commenter on John's post affirmatively defended such repetition:
... isn’t a relevant question how many of the people who should have read a paper when it first appeared, e.g. because they’re working on the same topic, did read it? In an ideal world the answer would be “all of them.” In the real world (except maybe in some hard sciences?) it’s usually “less than all” and in my discipline of philosophy it’s often “a lot less than all.” Even if a paper appears in the most prominent possible journal many people writing on the same subject won’t have read it. So re-presenting its main idea along with some new material in a follow-up paper increases the number of people exposed to the idea, not by 100% perhaps but potentially by quite a lot. Ideal writers might never repeat themselves, but then ideal readers would never benefit from repetition.
As another commenter observed:
... you tend to rewrite similar material for very different audiences. I am often writing articles from the same set of original findings for both technical and non-technical audiences. So a lot of the data description and findings are close to identical but the intro, explanation, and the description of methodologies varies a lot. I’ve decided to copy some material verbatim because I like the way I wrote it the first time and think rewriting it would make it less clear.
In my own work, ideas now tend to cycle between the blog, TCS columns, law review articles, book chapters, treatises, teacher's manuals, and so on. Once you've got a pretty well-polished idea, which appropriately works its way into multiple sources, why do you need to keep paraphrasing it over and over again?
One of the commenters on John's post also made a good point about the terminology:
Why does the academic community use this term, “self-plagiarism?” What is the value that this label is supposed to serve? After all, it’s not real plagiarism, in the sense of stealing ideas, because, well, the author is entitled to steal his/her own damn ideas. Nobody is being defrauded (unless it’s being done by a student, in a class, for a grade). It seems that the objections quoted above are … rather di minimis, and could easily be levied against a host of other work that doesn’t get that oh-so-condemnatory word “plagiarism” attached.
On the other hand, there is nothing quite so easy to rationalize as that which is in one's own self-interest.