Turnitin Similarity is a tool to support the detection of plagiarism by flagging instances of text similarity that may constitute plagiarism; however, it does not determine whether plagiarism has occurred. Each Similarity Report and its similarity score—the percentage of matching or similar text that has been uncovered—serves to equip educators with powerful insights to make their own, informed judgment call on whether a student’s content is plagiarized and if it was likely intentional or inadvertent and borne from a skill gap. Access on-paper highlights, filtration options, and flag insights that allow users to scrutinize the source of text matches and identify discrepancies, such as replaced characters or hidden text.

When a paper is submitted to Turnitin, a detailed Similarity Report is generated by breaking down text into phrases with assigned IDs and comparing them against seven trillion matches in Turnitin’s comprehensive database , including internet articles, scholarly publications, and student papers. Using natural language processing and strict matching techniques, Turnitin algorithm minimises false positives and flags unusual content for review. Alongside Turnitin’s default settings, the Similarity Report’s degree of accuracy further depends on user-configured settings, which allow educators to refine the percentage-based similarity score to align with their assignment requirements.

The Similarity Report’s similarity score is the percentage of text in a submission that matched against other sources. If students use any text from source material to support their work, such as a quote, it will be reflected in this score. Instructors have the option to use the report’s match exclusion feature to exclude citations or bibliographic information from affecting a student’s score. Your institution may or may not have assigned a number as an acceptable threshold for assignments, but keep in mind that there is no ‘right’ or ‘wrong’ number to receive as a score. Use the report insights and score within your review process to understand a student’s reliance on source material and make your own determination if any plagiarism or improper attribution is present.

While the Similarity Report is a great resource to check student work for possible plagiarism, the true power of the report is realized when it’s used as a formative assessment tool to strengthen academic writing skills and improve learning outcomes. Utilize details and data from a student’s paper and report to have an informed conversation about how they can make changes to improve. For instance, use the report to identify any areas that are exceptionally heavy on similar text to have an informed dialogue with students on how to improve. Consider conducting a lesson to review with students effective quoting, paraphrasing, and summarizing, and ask them to rewrite that section of text, reducing the amount of similar text within their writing.

Turnitin Similarity customers can access AI writing detection through our product add-on, Turnitin Originality. Once enabled, Turnitin’s AI writing indicator is linked to the Similarity Report and shows an overall percentage of the document that AI writing tools such as ChatGPT may have generated. It also includes the detection of AI-generated content that may have been paraphrased using a text spinner.* With intuitive navigation, users can easily switch between different report functionalities, such as the flags panel and integrated AI writing report. View aggregated AI scores across submissions over a period of time to understand the scale of usage.

_{*Feature available in English only}