Duplicate Publication and Salami Slicing
Duplicate Publication and Salami Slicing in Academic Research · Also known as: Redundant Publication, Overlapping Publication, Fragmented Research
Duplicate publication occurs when the same research data are published more than once without acknowledgment or justification, presenting the same or substantially similar results as previously published work. Salami slicing is the related practice of dividing the results of a single study into the smallest possible publishable units and submitting them as separate papers to multiply publication counts. Both practices artificially inflate research output, mislead readers, and violate ethical standards upheld by the Committee on Publication Ethics (COPE) and research integrity organizations worldwide.
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Method map
The neighbourhood of related methods — select a node to explore.
When to use it
Apply these concepts when planning a multi-paper research program, especially in cohort studies or longitudinal projects where temptation to slice exists. Use them when submitting a manuscript to evaluate whether results overlap with prior publications. Apply when reviewing literature to identify potential duplicate data. Use as a guideline when designing secondary analyses on published datasets—ensure the new research question and outcomes are sufficiently different.
Strengths & limitations
- Clear definitions provided by COPE and research integrity bodies prevent unintentional misconduct.
- Standards promote efficiency of the peer review system and protect the integrity of the research record.
- Explicit disclosure requirements (e.g., stating prior publications) allow editors and readers to judge novelty fairly.
- Enforcement through retraction and investigation discourages future misconduct.
- Grey area between legitimate secondary analyses and salami slicing—judgment required.
- Large cohort studies or longitudinal projects may naturally produce multiple papers with overlapping samples; justifying novelty can be challenging.
- Detection is difficult if data are published in different languages or in low-visibility journals.
- Minor variations in inclusion criteria or outcome measures may hide substantial overlap.
Frequently asked
Is it duplicate publication if I publish results for different outcomes from the same study?
Not if outcomes are substantially different and not specified in a prior publication. For example, if a trial first published cardiovascular outcomes and you later publish metabolic outcomes from the same cohort, this is justified as a secondary analysis—provided you clearly state it is from a previously published trial and properly attribute the earlier work.
Can I publish the same data in a journal and a conference proceeding?
Only if disclosed and if the journal allows it (many do for conference abstracts). Full journal articles and full conference papers presenting the same results should not be published without explicit acknowledgment and justification. The journal should know that a similar paper is or has been presented elsewhere.
What is salami slicing exactly? How do I know if I'm doing it?
Salami slicing is splitting one study into multiple papers with minimal novel content in each. For example, if your study measured 20 outcomes and you publish 20 separate papers, each reporting only one outcome with identical methods, this is prohibited. Legitimate reasons for multiple papers include methodological focus (one paper on methods, one on results), pre-specified subgroup analyses, or genuinely separate research questions. If you must ask whether each paper is justified, the answer is likely no.
If I find I accidentally published the same data twice, what should I do?
Contact the journal editors of both papers immediately. Provide a full explanation and documentation of the timeline (e.g., you forgot the earlier publication, it was under a different author order, etc.). Cooperate with their investigation. Even inadvertent duplication results in retraction of the later paper and a correction notice, but self-reporting and full transparency mitigate consequences.
Does the 'related articles' section of papers mean duplication is acceptable?
No. Listing a related article acknowledges that prior work exists, but the new paper must present genuinely new results or analysis. Simply relabeling or reframing identical results is not permitted.
Sources
How to cite this page
ScholarGate. (2026, June 3). Duplicate Publication and Salami Slicing in Academic Research. ScholarGate. https://scholargate.app/en/publication-ethics/duplicate-publication
Which method?
Set this method beside its closest kin and read them side by side — the library lays the books on the table; the choice is yours.
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