With in-the-classroom courses, class size has a big impact on the quality of the course: ~ 5 students, makes for a nice chat, but maybe the course will suffer from a lack of ideas from classmates. ~ 10 students, the teacher knows everyone and student contributions are valuable. ~30 students, the teacher lectures a lot, students are limited in their discussions. >60 students, half of the class sleeps, the teacher can't spend much time checking your work, but maybe can offer some help after class. >150 students, the teacher lectures 98% of the time, the teacher won't take many questions in class and won't care about "knowing you". >300 students, the teacher doesn't want to know you, will hide behind a wall of graduate students, won't personally answer any questions or look at your work. With distance courses, I'm sure the dynamic is different. Do On-line teachers use graduate students? What size of class do you think is ideal for a distance course?
In my own opinion should be between 20 to 30 for full-time instructor...15 - 20 for part-time instructor.
There are some institutions that attempt to control costs by enrolling large amounts of students (e.g. 50 or more) into a single course section with a single instructor. I do not believe that this is a good model. We cap our online undergraduate courses at 25 (4 less than most of our face-to-face courses). Graduate courses are smaller than undergraduate and doctoral courses have around 10.
