Most courses require that students make one post and one reply to another student's post (not necessary that the other student be working on the same course, or even the same degree program)--for each course module they work on in each course. In addition, students may make "extra" posts and replies (beyond those required in the course) to gain credit toward the required 10 hours of collaboration expected in most courses. (Each extra post and reply together count as one hour of collaboration).
For specific details on how to access WISR's online forum, go to: https://sites.google.com/wisr.edu/collaboration-in-wisr-courses/online-forum
For suggestions on how to write solid and meaningful posts and replies to WISR's online forum, please read the gudielines and tips in the section, "Online Forums" at: https://sites.google.com/wisr.edu/collaboration-in-wisr-courses/home