Canvas' Turnitin integration allows for you to check for academic integrity violations in written assignments. To activate this plagiarism detection tool, you will have to first create an assignment in Canvas.
Select "More options" from the Assignment pop-up.
Scroll down to "Submission Type;" select "online" from the dropdown menu and check "File Upload" as the Online Entry Option. You can restrict the file type to .doc or .docx.
Next, go down to the Plagiarism Review section and pick "Turnitin" from the dropdown. You can choose the settings that you prefer and save those initial selections for future use. For instance, you can save if and/or when the student can see Turnitin report for their submission. You can even save your Turnitin settings for future reference by checking the box next to "Save as default settings" at the bottom of the Plagiarism Review box.
After students submit their work, the Turnitin tool will run checks on students submissions and color codes the originality of the student work with flags that appear in the Canvas gradebook (in Grades). A blue flag means that the submission contained original content, green means there is some overlap in content between the student's submission and other sources, and a red flag is the greatest cause for concern.
When you are in a student submission with a green or red flag, in the top left corner of the submission will be the color-coded flag with a percentage listed inside of the flag. This is the similarity score. The higher the percentage, the more concerning the originiality of the student's work. You can click on the color-coded flag with the score to open the Turnitin feedback studio to check what the software has detected, inluding direct links to the other sources.
In order to check for students providing the same submissions to an assignment, it is best to wait until all the submissions are entered before starting to grade student work.