Similarity Reports provide a summary of the matching text found in a submitted paper. The percentage indicates the overall similarity index of the paper, based on how much matching text was found. The highlighted text in your document is color coded and numbered to match the sources on the right. Turnitin does not have a guide to what is a good or bad percentage. It all depends on the assignment type and what threshold the instructor has set. Research papers tend to have a higher percentage since there is more content from other sources. Please contact your instructor regarding the interpretation of your results (eg. what is "good" or "bad").
A breakdown of the indexes with the color codes are listed below:
0% (a valid result)--Blue icon
Turnitin does not tell Instructors whether a paper has or has not been plagiarized. Similarity Reports are simply tools to help instructors locate potential sources of plagiarism, or text which may have been incorrectly cited.