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 (as a percentage of the total text in the submission). A breakdown of the indexes with the color code is listed below:
0% (a valid result)--Blue icon
Once you see the percentage icon, it means that the report has generated. If you click on the icon, the report will load for you.
Turnitin does not determine 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. Therefore, only instructors can deem what is a "good" or "bad" score, as interpretation of the data can only be made by the instructor.