Name your courseroom. We'll take it from there.
An eight-week teaching block. Several run consecutively through the year, so students can enrol more or less continuously. A single block on its own is a short sprint; the difficulty appears once two or three run straight into one another with no interval between them for catching anything up.
Most modules ask for an opening post plus two responses to classmates. Individually these are small, and across eight modules they consume more hours than anything else in the course. Responses are where marks disappear most often, since the criteria reward engaging with an argument rather than agreeing with the person making it.
Because the manual follows the discipline rather than the university. Humanities and theology courses commonly use Turabian while nursing and business use APA, and one student can be running both inside the same eight weeks. The manuals differ visibly in how a citation appears in text and how the source list is titled and ordered.
Most modules contain one. None is individually difficult, which is precisely why they get deferred until several sit outstanding together. Treating each as part of its own module, rather than as something to return to later, is the simplest way to stop a compressed term becoming unmanageable in its second half.
As many as your program permits, and continuous enrolment is common. What accumulates across them is unfinished work: a module left partly done does not close when its block does, and the habit travels forward with you. Planning across the blocks instead of one at a time is what keeps them sustainable.