"Grading Rubrics for Online Discussions" (online resource) provides separate "analytic discussion forum grading rubric[s]" for undergraduates and graduates:
Assessment and Testing
"Participation Policy Examples" (online article) presents a collection of participation polices, ranging from a brief three-sentence statement to a detailed three-paragraph breakdown of marks.
Two articles explaining in detail how team tests/collaborative exams work (i.e. tests done first individually and then re-done in teams), how they are implemented in the classroom, and how they can complement conventional testing and student learning.