Compare these students:
- One starts the quiz, answers 2 questions, then spends 30 minutes thinking about questoin 3 without touchting their computer, then inputs the answer.
- One starts the quiz, answers 2 questions, gets up, goes to the toilet, comes back, and continues workng.
- One starts the quiz, answer 2 questions, gets up and leaves the exam room never to return.
- All students start the quiz and answer some questions. Fire alarm goes off. All students leave the room.
From the Moodle server, all these senarios look identical (until the student continues their attempt).
If the student does continue their attempt from a different computer, then that will show in the Moodle logs. The IP address will change. So, just tell students that the jsut do the whole quiz from one computer, and that you will monitor this through the logs, then do that.