My own children have had assignments with a due time of midnight on a certain day. I have set some deadlines similarly, thinking I was giving students more time to complete and turn in assignments. It never occured to me to be available to that time (although I do tell my kids they may email until 9pm the night before a test or major assignment). The rubric for participation on the discussion boards is great. I wish my Master's instructors had used something similar, for althought they articulated the same requirements, posts such as "Thanks, you made me really think about that" earned equal credit with ones that discussed confirming or negating research in response.
