You are encouraged to visit other sessions as often as you like, so long as the total number of students in the room does not exceed 20. Please conduct yourself as a polite and silent guest. As a visiting student you may not speak unless directly addressed by the tutor.
However, if you cannot attend your own session due to an irreconcilable scheduling conflict (and only then), you may attend a different session as a substitute for the one you must miss. Please notify your mentor of this change. In such a case you should participate as if you were in your own group.