Self-plagiarism: unintentional, harmless, or fraud?

THE LANCET

Volume 374, Issue 9691, 29 August 2009-4 September 2009, Page 664

Editorial

http://dx.doi.org/10.1016/S0140-6736%2809%2961536-1

The intense pressure to publish to advance careers and attract grant money, together with decreasing time available for busy researchers and clinicians, can create a temptation to cut corners and maximise scientific output. Journals are increasingly seeing submissions in which large parts of text have been copied from previously published papers by the same author.

Whereas plagiarism—copying from others—is widely condemned and regarded as intellectual theft, the concept of self-plagiarism is less well defined. Some have argued that it is impossible to steal one's own words. The excuse editors hear when confronting authors about self-plagiarism is that the same thing can only be said in so many words. This might sometimes be legitimate, perhaps for specific parts of a research paper, such as a methods section. However, when large parts of a paper are a word-for-word copy of previously published text, authors' claims that they have inadvertently used exactly the same wording stretch credibility.

There is a clear distinction between self-plagiarism of original research and review material. Republishing large parts of an original research paper is redundant or duplicate publication. Publishing separate parts of the same study with near identical introduction and methods sections in different journals is so-called salami publication. Both practices are unacceptable and will distort the research record. Self-plagiarism in review or opinion papers, one could argue, is less of a crime with no real harm done. It is still an attempt to deceive editors and readers, however, and constitutes intellectual laziness at best.

Deception is the key issue in all forms of self-plagiarism, including in reviews. Few editors will knowingly republish a paper that contains large parts of previously published material. Few readers will happily read the same material several times in different journals. An attempt to deceive amounts to fraud and should not be tolerated by the academic community.