Examples
Worked examples
- Is an instance
Submitting the same randomised-trial results to two journals simultaneously, with one accepted and published while the other is still in review.
Counter-examples
Looks similar, but isn't
- Not an instance
A conference abstract followed by a full journal article that cites and expands the abstract with additional analysis.
Editorial commentary
Duplicate publication (also called redundant publication) is publishing an article that overlaps substantially in hypothesis, data, methods, results, and conclusions with an article the same authors have already published, presenting it as new work, without disclosing the relationship to either journal’s editors. The operational question is not whether any text is identical, but whether a reader encountering the second paper alone would reasonably believe they were reading a distinct, independent study rather than a re-presentation of already-published findings.
What it is not
Duplicate publication is often conflated with salami slicing, but they move in opposite directions: duplicate publication republishes the same results as new, while salami slicing splits new, non-overlapping results from one dataset across several undisclosed papers. Duplicate publication is also distinct from self-plagiarism (text recycling), which concerns reuse of an author’s own prior wording or passages, typically in a Methods section, rather than republication of a full dataset and its findings as a new study. ICMJE recognizes legitimate secondary publication — for example, translation into another language for a different readership, or a conference-to-journal progression that adds substantial new analysis — as acceptable when both editors agree in advance and the relationship is disclosed and cross-referenced in both versions.
Why it matters
Undisclosed duplicate publication inflates the apparent evidence base for a finding, biases systematic reviews and meta-analyses that treat each publication as independent evidence, wastes peer-review and editorial capacity, and typically breaches the exclusive-submission agreement authors sign with the first journal.
In practice
Because confirmed duplicate publication misrepresents novelty to readers and reviewers, COPE’s guidance treats retraction of the later, undisclosed publication as the typical remedy, in contrast to salami slicing, which more often draws a correction or editorial note. Authors intending a legitimate secondary publication should secure written agreement from both editors before submission and cross-reference the original work explicitly in the second version.
Related terms
See also salami slicing, self-plagiarism, and research misconduct.
References
- ICMJE Recommendations (current edition)
- COPE Flowchart: Suspected Redundant Publication (2013, updated 2018)
Also known as
redundant publication · dual publication
Machine-readable encodings
Use in your systems
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