What Is Self-Plagiarism? Examples & How to Avoid It

Self-plagiarism happens when you reuse work you have already submitted or published and present it as new, original work for a different purpose, without saying that it has been used before. It is also called duplicate submission, duplicate publication or text recycling, and it is one of the recognised types of plagiarism.

The words are yours, so the problem is not stolen authorship. The problem is the implied claim that the work was produced for this assignment or adds something new to the record.

Self-plagiarism looks different for students and researchers.

• Resubmitting an essay, or large parts of it, from an earlier course or year.

• Submitting the same paper to two courses that have overlapping assignments.

• Copying paragraphs from your own published article into a new article without quotation marks or citation.

• Publishing substantially the same study in more than one journal.

• Splitting one study into several thin, overlapping papers (sometimes called salami slicing).

• Including a published article as a thesis chapter without stating where and how it was published.

In coursework, each assignment is meant to show what you learned for that task. Recycling old work gives credit twice for one effort and skips the learning the new assignment was designed to produce.

In research, undisclosed reuse makes findings look more numerous or more novel than they are and can mislead readers who rely on the published record. Publishers may also hold copyright in your earlier article, so reusing it can raise permission issues as well as integrity ones.

Building on your earlier work is normal, provided you are transparent. A final-year project that develops an earlier proposal, a thesis that incorporates your published papers, or a methods section that reuses a precise protocol description can all be legitimate.

The conditions are the same each time: get approval where it is needed, disclose the reuse clearly, cite the original, and follow the specific rules of your course, institution or journal.

The principle is simple: treat your past self like any other author.

• Cite your earlier work whenever you use its ideas, findings or wording.

• Put any reused wording in quotation marks with a citation, or rewrite it for the new context.

• Ask your instructor or supervisor before building on a previously submitted assignment, and keep their approval in writing.

• Start each new assignment or paper in a fresh document instead of editing an old one.

• Keep a simple log of what you have submitted or published, and check your draft before you submit it.

Similarity tools can only match text they can search. If your earlier work is published online or stored by the service your institution uses, reused passages can appear in a similarity report as matches against your own name, just like any other source.

A disclosed, cited match is not misconduct — it shows the reuse is transparent. PlagCheckr does not intentionally add your submitted documents to a public plagiarism database, so checking a draft with it does not create a future match against yourself.