Self-plagiarism is the reuse of an author’s own previously published words, data or findings in a new submission without disclosure, and duplicate publication is its most serious form: submitting substantially the same paper to a second journal or assessment exercise as if it were original. Research offices need a written policy because UK universities define and detect the practice differently from how journals, guided by the Committee on Publication Ethics (COPE), handle it after publication.
Self-plagiarism is the reuse or recycling of one’s own previously disseminated text, data or ideas without acknowledging their prior publication, a definition close to that used by the University of Glasgow’s postgraduate research code of practice. It is not theft of someone else’s intellectual property, but it can mislead readers about the novelty of the work and, where copyright has passed to a publisher, breach that publisher’s rights.
What is self-plagiarism and how does it differ from duplicate publication?
Self-plagiarism covers several distinct behaviours, and a policy that treats them as one problem will under- or over-punish researchers. Miguel Roig’s widely cited taxonomy, referenced in University of Glasgow guidance, separates duplicate publication (the same paper submitted to two venues), redundant publication (substantial overlap with limited new content), augmented publication or “meat extension” (a small data addition dressed up as a new study) and segmented publication, also called salami-slicing, where one dataset is fragmented into several minimal papers.
- Text recycling — reusing methods or literature-review paragraphs verbatim across papers, generally treated less severely if disclosed.
- Duplicate (redundant) publication — near-identical results, data and conclusions appearing in two outlets without cross-reference.
- Salami slicing — splitting one study into the minimum publishable unit to inflate an author’s output count.
- Double-dipping — submitting one piece of coursework for credit in two modules or degrees, the most common student-facing case.
The common thread across all four is the absence of a clear statement telling the reader, editor or examiner that the material has appeared before.
How do UK universities define and detect self-plagiarism?
UK institutions typically fold self-plagiarism into their academic integrity or research misconduct code rather than issuing a stand-alone policy. The University of Glasgow’s postgraduate research code of practice defines it as republishing “a work in its entirety or reuses portions of a previously written text while authoring a new work,” explicitly flagging the copyright-infringement risk. Detection at the institutional level is almost always automated.
Text-matching software, principally Turnitin, retains a database of every previous submission by a student or researcher within a subscribing institution, so recycled coursework, theses or preprints are matched even when no external source is involved. This is a structural difference from journal-side detection, which typically relies on CrossCheck/iThenticate comparisons against the published literature rather than an institution’s own submission archive — meaning a student’s unpublished prior assignment may be invisible to a journal but immediately flagged by a university’s own repository.
Institutional handling also sits inside a wider governance structure: UK signatories to the Concordat to Support Research Integrity, coordinated by Universities UK, commit to transparent, proportionate misconduct procedures that must cover publication practices, including duplicate and redundant publication, not only fabrication and falsification.
Where do COPE rules diverge from institutional academic-integrity rules?
Journals and universities are answering different questions, which is why the same manuscript can trigger two separate, non-identical processes. A journal editor following COPE guidance is asking whether the scholarly record needs correcting; a research office is asking whether an individual has breached a code of conduct.
| Dimension | COPE / journal response | Institutional / research office response |
|---|---|---|
| Primary concern | Integrity of the published record and reader transparency | Conduct of the individual against the institution’s code |
| Typical trigger | Editor or reviewer recognises overlapping text or data post-submission | Text-matching software flags a submission at intake (thesis, assignment, grant report) |
| Guidance used | COPE flowcharts on suspected redundant (duplicate) publication; ICMJE recommendations on overlapping publications | Institutional academic integrity policy, often referencing the UK Concordat to Support Research Integrity |
| Possible outcomes | Correction, expression of concern, or retraction; author notified via publisher | Formal warning, mark penalty, mandatory training, or referral to a misconduct panel |
| Who acts | Journal editor, in consultation with the publisher and, where relevant, the author’s institution | Research integrity officer or academic conduct committee |
COPE’s own case files show the practical effect of this divide: its published discussion of a self-plagiarism case notes forum members expressing sympathy for an author while still requiring correction of the record, because the editorial remedy (correcting readers) is independent of any judgement about the author’s intent. A research office cannot outsource its own disciplinary decision to a journal’s correction, and a journal cannot substitute for an institution’s misconduct process — each must run its own track, and a policy that assumes one covers the other will leave gaps.
What should a research office’s self-plagiarism policy include?
A workable policy needs to do more than restate the definition. Based on the divergence set out above, a research office policy should:
- Define self-plagiarism with named sub-categories (duplicate, redundant, augmented, segmented publication) rather than a single umbrella term, so cases are classified consistently.
- State explicit exceptions — conference-to-journal expansion, translations for non-English audiences, and plain-language summaries — provided each carries a disclosure statement to editors and, where relevant, examiners.
- Set out the detection method (which text-matching tool, what similarity threshold triggers review) so staff and students know how matches are surfaced.
- Separate the reporting line for student cases (module leader or academic conduct office) from staff/researcher cases (research integrity officer), since the applicable code differs.
- Require researchers to disclose prior publication of overlapping material to editors at submission, mirroring ICMJE’s overlapping-publication recommendations, rather than leaving disclosure to be discovered.
- Reference COPE’s flowcharts on suspected redundant publication as the institution’s expected response when a journal makes contact about one of its authors.
Policies that omit the disclosure-based exceptions tend to produce the most complaints, because researchers legitimately reworking a conference paper, a thesis chapter or a policy briefing for a new audience are treated identically to authors concealing duplicate results.
Common questions about self-plagiarism
What is an example of self-plagiarism?
A common example is submitting the same coursework essay for credit in two different modules, or publishing a near-identical dataset and discussion in two journals without cross-referencing the earlier paper. Both withhold from the reader or marker that the work has been previously submitted or published.
Will Turnitin detect self-plagiarism?
Turnitin can detect self-plagiarism because it retains a searchable archive of every prior submission made within a subscribing institution. A student’s own earlier assignment, thesis draft or conference paper will typically be flagged as a text match, even where no external plagiarism has occurred.
What happens if a researcher is found to have self-plagiarised?
Outcomes depend on which track applies. Journals follow COPE guidance and may issue a correction, expression of concern or retraction; universities apply their own academic integrity code, which can range from a formal warning to referral to a research misconduct panel for staff, or a failed module for students.
How can researchers avoid self-plagiarism when reusing their own work?
Researchers should cite their own prior work as they would any other source, disclose overlapping material to editors in a cover letter, and obtain explicit permission from co-authors, supervisors or publishers before reusing substantial text, data or figures in a new submission.
Implications for research offices
The gap between journal-side and institution-side handling is not a loophole; it is two accountability systems answering different questions about the same document. A research office that documents this distinction explicitly — rather than assuming a COPE correction closes the institutional file — will resolve cases faster and more consistently.
As text-matching tools extend coverage to preprint servers, thesis repositories and grant reports, more duplicate-publication cases will surface at intake rather than after publication. Institutions that name detection thresholds, disclosure exceptions and dual reporting lines now will handle that shift better than those relying on a general-purpose plagiarism clause.
For related institutional context, see CASRAI’s overview of research administration practice and its explainer on authorship criteria, which intersects with duplicate-publication disputes over who is entitled to reuse shared material.
