I would like to say that it is often rather difficult giving a series of lectures like this without the possibility of comebacks or discussion, and not knowing whether what one is saying finds an echo in those who are working on a thesis or a master’s degree, whether it provides them with possibilities for reflection and work … On the other hand, you know that in this institution … we cannot give closed seminars, reserved for just a few auditors… All the same, what I would like, not so much for you, but selfishly for myself, is to be able to meet Off-Broadway, outside of the lectures, with those of you who who could possibly discuss the subjects I will be talking about this year, or that I have talked about elsewhere and previously.
Michel Foucault, The Government of Self and Others, Lectures at the College de France, 1982-1983 Lectures at the Collège de France (Volume 7). Translated by Graham Burchell; Edited by Frédéric Gros; General Editors: François Ewald and Alessandro Fontana; English Series Editor: Arnold I. Davidson, London: Palgrave Macmillan, 2010. p. 1
Random thoughts in response
Foucault commented a number of times on the difficulty of lecturing at the Collège de France. These lectures were public and anybody could attend. On a couple of occasions he tried to open the floor up to questions but this didn’t really work given the large number of people in attendance. He remarked that he would see the same people attending week after week and would wonder who they were and what they thought of his lectures, but there was no means of making contact with them. At the end of each lecture, people would race to the front podium where he sat, not to ask him questions but to collect their tape recorders. In truth, it was actually rather difficult to approach Foucault after these lectures. He would be surrounded by an intimidating group of young men and everything in their demeanour and his own demeanour suggested that you could only approach him at your peril.
Foucault tried to counteract this alienating effect by organising private work seminars where specialist work could be done on subjects he found of interest. Foucault enjoyed these kind of specialist collaborations. Although Foucault did not regard his lectures at the College as a ‘teaching activity’ more as ‘public reports’ on his research  it might be worth drawing attention to comments he made elsewhere on the difference between the lecture and the seminar when these do function as teaching tools. In the lecture, he says, in spite of appearances, there is less of a relation of power between the teacher and the students than in a seminar. The auditors of a lecture can freely adopt a take it or leave it approach to the content and could admire the lecture (or not) as one would admire a well-crafted shoe. Foucault comments
‘I see myself more as an artisan crafting an object and offering it for consumption rather than a master making his slaves work’. On the other hand, seminars with discussion meant that by the end of the series, students could no longer be sure whether their ideas were their own or had been subtly and insidiously moulded by the seminar leader during the course of discussion. 
 Michel Foucault, “Society Must Be Defended” Lectures at the Collège de France, 1975-1976. Translated by David Macey; Edited by Mauro Bertani and Alessandro Fontana; General Editors: François Ewald and Alessandro Fontana; English Series Editor: Arnold I. Davidson, London: Palgrave Macmillan, 2003 p. 1
Michel Foucault, ‘Conversation avec Michel Foucault’, Dits et Ecrits, vol II. Paris: Gallimard, 1994, pp. 190-191.