**Choose whether you want to index the submission to the Turnitin Database via Submission Indexing**
When you check the box "Submission Indexing", student assignments will be added to the general Turnitin Database. This will allow for Turnitin to grow their database, so that more plagiarism can be detected.
For example: if a paper is indexed, Turnitin will detect papers that are handed in multiple times by students among various courses.