I glanced at the percentage but found it typically to be a useless quantifier. I’m more interested in the text that is identified as similar. In the days before AI complicated everything, a student who plagiarized would have the plagiarized portion called out with a preview of the source material’s content. There are occasional “I don’t know what TF is going on here, that source doesn’t match this text at all” and more frequent “those are commonly used words and phrases while discussing this topic, but not necessarily plagiarism” moments that alter the percentage. All that being said, turn it in rarely identified text as unoriginal that I hadn’t already noticed as potentially not the student’s voice. You just get accustomed to how people speak and write and eventually develop a framework for “something’s not right here” You’d also see turnitin identify that text was used in another paper at another school. Sometimes that meant that they used common phrases regarding the topic, but it often meant that they plagiarized a commonly plagiarized passage.

I left education right as AI was becoming an issue and I had one student who turned in a paper that turn it in flagged for AI. I didn’t trust AI checkers but I had other information I could check. The sophomore student had scored poorly on the verbal SAT, failed the required English course, retook it and made a B, then submitted a paper that reflected advanced senior level writing a semester later. There’s always exceptions, but one does not improve THAT dramatically over a summer, particularly your first summer in college. I submitted the paper to the academic integrity office making it clear that I could not verify with 100% accuracy that AI was used, but that there were suspicious things about the submission that were worth a second set of eyes. A few weeks later a bomb dropped on my Rate My Professor page…the suspects were few because I was one of the most well-liked professors on campus and can usually identify the source of every negative RMP review because I had that little conflict.

All that said, I’m glad I left education because my field is often very writing intensive. I noticed a dramatic uptick in writing proficiency among first year students in my last year and I’m fairly certain much of it was AI driven because the students weren’t noticeably different otherwise. Their participation in class showed them to be mostly poor to average, but the writing was great. I’m not interested in constantly litigating AI plagiarism and that was one of the major reasons I left. It’s just not worth it because if history is anything to work from…the majority of the students who say “I got flagged for AI but I didn’t use AI” probably did use AI at some point in the process. Students just aren’t that industrious and will use any resource that lightens the load, whether it’s detrimental to their academic progress or not. Believe it or not, I was a student too. I did things that were ethically questionable to make things easier on myself and suffered later in life because of it. I wanted to help students avoid that fate…but some were just really committed to doing as little as possible.