I also teach a 4 hour class. I have found that spreading out a 4 hour lecture into 2 day blocks helps the student absorb the information much better. In addition, we do activities and question and answer sessions throughout the session to keep the students motivated. This also insures the student understand the topic before moving on to the next part of the lecture. As we all know it does take a lot of energy doing long lectures, it is also very taxing on students to sit still that long. Especially when my class starts at 7:00 am and most of my students just woke up.
