Sadly, there is no way to send already uploaded assignments to the Turninitn service. Once the first student uploads their work, Moodle will no longer be able to establish a connection to Turnitin for the assignment.
Nevertheless, there are a few solutions you could try, depending on your case:
Case #1 – You need to (i) see a Turnitin report or use the GradeMark feature for all submissions and/or (ii) save all submissions to the Turnitin database to protect future submissions to similar assignments
- You could create a new Turnitin-enabled assignment and ask students to download their submissions from the old one and re-upload them. This will be the simplest and most transparent option if the due date for the assignment has not passed or you feel you can offer a fair extension to all students. If you are very concerned about assignment security, you could perhaps do this in controlled conditions (i.e., make the new assignment visible in class time and ask students to reupload with no prior warning).
- You could set up a “hidden” assignment, set the “Submission Types” > “Maximum number of uploaded files” setting to the maximum value of 20 files, and in the Turnitin Plagiarism Plugin settings set the “Store student papers” setting to “Standard repository”. You can then temporarily switch your own Moodle role to “student”, and upload the students’ submissions in batches of 20 as needed.
Case #2 – You need to see a Turnitin report for one or a few suspicious submissions:
- You could set up a hidden assignment, set the “Submission Types” > “Maximum number of uploaded files” setting to the maximum value of 20 files, in the Turnitin Plagiarism Plugin settings, set the “Store student papers” setting to “No repository”. You can then temporarily switch your own Moodle role to “student”, and upload the students’ submissions in batches of up to 20 as needed.