And obviously, before the exam and at some point, we wanna be going through every single question because one of the other concepts in effective studying is called spaced repetition.
The second reason is that some of the participants may not in fact have had time to read your paper, although they may have glanced through it quickly.
That sounds pretty obvious, but you'd be surprised how many people just look at the thing they're memorizing and think that they'll have it in their memory just by going through it over and over again.