Last week, Budi Raharjo has posted about Limiting Time On Presentation (it's in Indonesian). He said in his post that most people stay focused for about 15 minutes at maximum. After that, he/she will lose focus and perhaps became sleepy. This happened on most of class meeting, not only in college, but also in school (elementary, junior high school, and senior high school). At most school, a class will be around 45 minutes and in college usually 50 minutes per credit. For example you took 3 credit class, then you (ideally) have to listen for the lecturer for about 3x50 minutes (that's 2,5 hours). Is it possible to do that without getting sleepy?
When i was studying at college, i had experienced listening for 50 slides of presentations. Is it effective? Well it depends on the material. Most of the time, it didn't work very well. That's why when i make presentations, i limit my presentations to around 20 slides (I had 37 at maximum, but i split this into two class). For me, this is quite effective. I'm not sure if this will work for you, but give it a shot
Comments are welcome