For an online, semester-long, three-credit class, how many posts/responses would be appropriate if these are the bulk of the weekly activities?
I'm thinking of giving them five questions and requiring three 10+ sentence posts and two 5+ sentence responses, but I don't know if I should require more responses to create more discussion or more posts in general, or if I should even differentiate from posts/responses? Thoughts?
I tend to ask five questions, with 30 to 40 students, each from a different supplementary reading, (in face to face intro-level classes, too). I require only one initial post and one or two reply responses each week but for ten weeks, rather than for every week, as this mitigates problems of my campus' late-registration period, of many emails on excuses, etc. (there still are some, of course, but fewer), etc. At the same time, I give students incentive to get going and not defer on this by awarding (minimal) extra credit for any beyond ten. That means that extra means extra, and such credit comes only after meeting the required minimum.
I do differentiate, with explicit instructions as to what they must do in initial posts and in responses. For example, in initial posts, they must use the textbook reading and the lecture and the supplementary reading. In responses, I have learned the hard way to force them to actually be responsive to a classmate by citing/complimenting a classmate for at least two points that the classmate made, addressing those, and again specifically from readings and/or lectures (but not all of the above, as in the initial assignment) -- but not just repeating what they used from the readings and/or lectures in the initial assignment.
I don't use sentences; I use number of words.
I based this design at first on what a colleague did in a comparable course, part of a two-course survey, but I have somewhat increased the workload since, although not to the extent that I understand that you foresee here. In part, I don't know if yours is an intro-level or upper-level course. I will be interested in other comments.