According to moore and marra's (2005) case study, which observed two online courses, students in the first course implemented a constructive argumentation approach while students in second course had less structure for their postings. as they stated, when instructors create online discussion board activities, they must answer at least two questions. these questions are: "what is the objective of the discussions? " and "how important are online discussions in comparison to the other activities that students will perform? " according to their findings, the discussion activities that were designed based on the answers to these questions can influence the quality and quantity of interactions (moore & marra, 2005).