A discussion works best when you set it up with a specific prompt and a clear expectation for engagement, for example one original post and two substantive replies by set dates. Build that structure in now, while you are designing the course.

For anything graded, build a Rubric: a small grid of criteria and performance levels. In Blackboard you have two options: build the rubric yourself, or let the AI Design Assistant draft one from your course context that you then review and refine. Either way, attach it to the assignment or discussion so students see the target up front and grading later goes faster and more consistently.