In their small groups, working only with their peers, all the students feel confident enough to start talking. They also can start to see how much they can learn from fellow students. The method also encourages preparation because I don't tell them in advance who will give the presentation each week, so need to prepare for that, and because they need to be supportive to fellow students, so there is peer-pressure, not just my insistence. The formal presentations also mean that every student, even the shyest, has to speak for 5-7 minutes in front of the whole group plus tutor, so the problem of public presentation begins to be broken down. Because of the focus on set questions, though many of these might be quite open-ended means that even if seminar discussions do wander into tangential issues from time to time, a new presentation always brings us back to the main focus.
Students also learn a lot from their fellows.
A few good students in a seminar can have an affect on them all, both by setting high standards and by encouraging the others to recognise what a student can manage. The students can recognise and learn from good presentations, as well as from their own performance. They can also be helped in preparing their own work by good students in the small group. I do much less talking in these seminars. It is also difficult for loud students to dominate.