What does my similarity score mean?
See Interpreting the Similarity Report.
If your instructor has enabled Turnitin for your assignment:
Any matching or highly similar text discovered is detailed in the Similarity Report that is available in the assignment inbox. Similarity Reports provide a summary of matching or highly similar text found in a submitted paper. It is perfectly natural for an assignment to match against some of the sources in our database. If you've used quotes and referenced correctly, there will be instances where we will find a match and that is totally OK! Below are some factors that may cause similarity scores that are considered acceptable, as well as some that are considered unacceptable.
Acceptable similarity factors
Unacceptable similarity factors
There is no set cutoff score that indicates whether a paper is “acceptable,” but the balance of acceptable and unacceptable types of similarity are considered in the overall review of the Turnitin similarity report. When most or all of the similarity comes from unacceptable factors and there is frequent similarity throughout the paper, it is a signal that revision is needed to create more original work.
For help understanding how to use the feedback you see from your instructor, learn from the Incorporating Feedback Guide from the Effective Writing Center.