and publication practices are essential for honest scholarly and scientific research. Most journals today are keenly aware of this: they create policies1-6 on these issues and expect authors to “be aware of, and comply with, best practice in publication ethics”5.This article discusses two widespread and related publishing practices that are considered unethical—duplicate publication and simultaneous submission. It draws on definitive international publication ethics guidelines.7-10
Duplicate (or redundant) publication is the publication of a paper that is substantially similar to a published paper by the same author, without acknowledging the source and without obtaining the permission of the original copyright holder.7,11,12 There may be superfluous differences between the original and the second paper, such as a new title or a modified abstract, but the data set and findings stay the same.13
Why is duplicate publication a problem?
of a paper without permission and/or acknowledgment is a serious breach of publishing ethics, for the following reasons:.
What do journals and ethical guidelines have to say about the issue?
Ethical and editorial committees7-9, 15,16and academic journals 1-3,5,6,17 explicitly instruct authors not to submit papers or variations of papers on studies that have already been published elsewhere. Several journals have stringent policies that require authors to send copies of older, related articles along with the submitted paper2,3,12 if the study findings and subjects overlap. Some journals are very specific and require that this be done when the overlap is more than a certain percent.2 Others permit only a few identical sentences; previously published results or larger portions of text taken verbatim from the author’s older publications, without acknowledgment, are not accepted.17
However, is permitted1,7,8 in the case of specific article types. These are:
While these exceptions can be made, authors must adhere to the following guidelines7,8 in these cases as well:
Dos and don’ts for authors7,15