When student submissions receive a 0% similarity score, it means that none of the text in the paper matches the enabled search sources. Instructors may also see the message There are no matching sources for this report.
Turnitin’s system looks for a minimum number of words in a sentence or paragraph structure to count as a match. A 0% score is more common in shorter papers (1-2 pages) and creative writing assignments where students are using their own words/voice.
If a student’s submission receives a 0% score, there are some assignment settings the instructor may be using that will result in a lower similarity score, such as using the exclude small sources settings.