I’m a little confused. Teachers usually assign students to hand in papers through institutionally connected plagiarism checkers, like Turnitin or Safeassign. Those do indicate what sources of possible plagiarism are indicated. (My students submit through Turnitin–I allow multiple submissions and it does not flag a student for similarities with their own work). This looks like some random business/website oriented checker–I am surprised if a teacher is telling students to use it. [Editing to add: it will note similarities to other students at other institutions, not just “publicly available” materials as mentioned in above post.]
But what’s more confusing me is–why would a student need to turn their paper in to a plagiarism-checker independent of submitting to class? The student should know what constitutes plagiarism and if they are doing it or not, right?
So I think I’m missing something here.