Turnitin is the most widely used plagiarism detection software in academic institutions, but it is widely misunderstood. Turnitin does not detect plagiarism — it detects textual similarity. The interpretation of similarity reports requires human judgment: a 20% similarity score might indicate serious academic misconduct or simply an appropriately cited literature review.
For a PhD thesis, a Turnitin similarity report is almost always required before submission. Most universities set a threshold — commonly 10–15% excluding references and quotations — above which the thesis must be reviewed by the supervisor or integrity officer. Understanding what drives your similarity score is the first step to reducing it legitimately.
The most common sources of high similarity in a legitimate thesis are: direct quotations (which should be clearly marked and kept to a minimum), shared methodological language (every researcher uses the same terminology to describe standard methods), previously published work by the same author that has been incorporated into the thesis, and institutional boilerplate text.
Paraphrasing is not a solution to similarity if the underlying ideas are not properly attributed. Changing a few words in someone else’s sentence while keeping the same idea and structure, without a citation, is still plagiarism — even if Turnitin does not flag it as a high similarity match. Genuine academic writing involves engaging critically with sources, not just rephrasing them.
At Thesis Writing Cafe, every document we write is original and passes Turnitin with a similarity report provided. We do not use templates or recycled content. If your existing thesis needs improvement to reduce similarity scores, we can help identify which sections need to be substantially rewritten and assist with the rewriting process.
