The topic of the three hour lecture seems to be coming up a lot in conversation. Have you been there? Teaching the three hour lecture that might sometimes feel like the six hour lecture?
In looking for suggestions from other faculty in other schools, I was somewhat surprised to come across these suggestions from a professor at NYU that dates back to 2000. Clearly, this is not a new issue, but I think Paul Brown’s tips still hold up:
There is another article on the Faculty Focus site that addresses the idea of teaching courses in blocks. You can find the article here: http://www.facultyfocus.com/articles/instructional-design/teaching-classes-that-meet-in-blocks/
The suggestions seem to be similar: divide your three hours into distinct blocks and alter your mode of delivery. Doing so will keep the content interesting for you and the students.