Students' Guide to Turnitin

• Regardless of the similarity percentage, you will need to analyze the report to determine whether the student plagiarized.
• You can exclude: Reference Lists, Short Phrases If the reference list is very long, you can exclude it as well as short phrases to bring the number down. Please refer to the Refining the Similarity Report website for more details. 
• Below the similarity number will be all the sources to which parts of the paper matched. There is a number next to each which tells you how much of the paper came from that source.

Some notes about the Similarity Report:

• The source which Turnitin matches may not be the original source. The quote above was pulled directly from Turnitin's User Guides, but it matched to a student paper which used the same quote.
• If the number seems excessively high, click the filter icon and see if you can exclude short phrases and references.

Source: https://guides.highpoint.edu/turnitin