@fncll interesting. From a practical standpoint I can imagine what a very difficult type of research this would be to conduct on a larger scale or with say a general undergrad population. It would take such care to set up.
For me as a teacher I work to be straight up- students know certain topics will be discussed from the handbook/outline and I give them full permission to participate or not as they wish. -nothing I'd see as sensitive, but for some it is a challenge to discuss their learning.