Teacher to Student This allows dialogues between
teachers and students. Dialogues can be started by either
teachers or students. In the lists of people, teachers only
see students and students only see teachers.
Student to Student This allows dialogues between
students. Teachers are not included at all in this type of
dialogue
Everybody This allows everybody in the Class to
start a dialogue with anybody else. Teachers can start
dialogues with other teachers and students, students can start
dialogues with other students and teachers.