[jfghi]

Ironically, the best detector for plagiarism would be a 15 minute conversation asking the student about their research and opinions on the topics written, kind of like interviewing someone who claims redis expertise on their resume.

[r_hoods_ghost]

This is essentially the Oxbridge tutorial system where you have an hour(ish) meeting once(ish) a week with one or two other students and your tutor and talk over what you've learned, are set an assignment or three and have to answer any questions about the last week's assignments. A slightly more scalable version is the seminar system where you have up to 10 students and a tutor and you do roughly the same thing. It only works if participation is mandatory, missing seminars / tutorials is penalised and tutors are given leeway to adjust grades based on semina performance or flag students who do really well on their essays but appear incapable of explaining or defending what they've written.