What is the purpose of discussion questions for an online course?

Question A – What is the purpose of discussion questions for an online course? Do the requirements for length and engagement with other students support this purpose?

Question B – According to Van Bramer and Bastin, “a progressive paper is one that students write one section at a time: as they add each new section, they go back and revise the previous parts based on actionable feedback from the instructor” (2013, J. Chem. Educ., 90 (6), p. 745). How do the assignments in PAD 510 exemplify a progressive paper?