Why did the Plagiarism Check not find my copied fragment?

If you copied a fragment from a source and the Plagiarism Check did not find it, there are four possible explanations.

You paraphrased the fragment

If you paraphrased the original text by using different words and/or changing their order, the fragment will no longer be detected by the plagiarism software.

You can test this by searching the fragment in double quotation marks on Google. If no results are returned, you successfully paraphrased. Note that you still need to cite the source of the original idea.

However, if Google did return a result but our software did not highlight it, this might mean that…

The source is not part of our database

The Turnitin database used by the Scribbr Plagiarism Checker contains 99.3 billion current and historical webpages and 8 million journal articles and books. However, it’s possible that the source you used is an inaccessible publication or a student paper that is not part of our database.

Even if you’re certain that the source is publicly accessible, it might not yet have been added to the database. Turnitin is constantly updating its database by searching the internet and adding new publications. You can expect the source to be added in the near future.

The “Exclude Small Matches” number is set too high

By default, the plagiarism report shows similarities of 9 words or more. If the fragment you copied is shorter than that, it will not be shown in the report.

You can manually adjust the minimum length in order to show shorter similarities. Find out how to do that here.

Your document was not readable

If you uploaded a PDF file, it is possible that your document is not machine readable or was converted to an image instead of text. As a result, no similarities will be found.

To test if the text in your PDF is readable, you can copy and paste the document into a text editor (e.g. Microsoft Word, Notepad, TextEdit). If the text editor shows the same text as the PDF, then the text will also be readable by our plagiarism software.

If you know that you used a fragment, but it wasn’t found by our plagiarism software, it’s best to paraphrase or quote it anyway (and be sure to cite the source). It’s always better to be safe than sorry!