Battle of the calendars: Quarters vs. semesters

On my campus, we teach on a quarter-system: Fall, winter, and spring quarters, with an optional summer quarter. Many faculty on my campus believe that a quarter-based academic calendar is less conducive to learning than a semester calendar. What do you think?


For the sake of comparison, I teach three courses per quarter, with the fall quarter running from late September to early December, the winter quarter from early January to mid-March, and the spring quarter from late March to early June. There are, I think, a couple of advantages to this sort of calendar. First, students end up taking a larger number of courses overall. In philosophy, this means that students end up being exposed to a larger cross-section of the discipline. Whereas on a semester system, students might, for instance, decide to take either ancient philosophy or medieval philosophy, students on a quarter system can probably fit both into their academic plans. I've also found that, on the quarter system, fewer students drop classes. It may not seem like a big deal, but suppose that after 2-3 weeks, you've determined that a class you enrolled in just isn't what you expected, etc. On a quarter system, you might opt to hang in, since you have about seven weeks left. In contrast, on a semester system, you have eleven weeks left. It may not seem like a big difference, but since the time costs of remaining enrolled are less on a quarter system, students seems to be a little more willing to stick with a course.

The quarter system also enables some course sequencing that might be awkward on a semester system. For instance, we offer a two-quarter logic sequence, of which the first course is required for philosophy majors. But many take the second course in the sequence as well, which gives them a better grounding in logic without forcing them to take a whole year's worth of logic.

But on the whole, the disadvantages of quarters probably outweigh the advantages. Here are the disadvantages:

1. It's absurdly fast paced, both for students and faculty. Everyone is constantly preparing for next quarter, administering midterms or finals, etc.
2. For faculty, it means preparing many more distinct courses. This can be pleasant in a way, but you spend an enormous amount of time on course design.
3. The cross-disciplinary breadth is counterbalanced by a lack of depth. It's very hard to teach any of the major subdisciplines of philosophy adequately in ten weeks. History surveys (ancient, modern) often have to neglect major figures or movements when taught on a semester calendar, so the quarter calendar only compounds the sense that the material is covered in a superficial way. I manage to teach a decent ethical theory course in ten weeks, covering egoism, utilitarianism, Kantianism/deontology, and virtue ethics, but I feel I give much of the material a 'fly over' treatment.
4. It makes independent projects challenging. Students wanting to write a thesis or do an independent study struggle to do anything meaningful in ten weeks. Figure 3-5 weeks to do the reading and research, another 3 or so to write a draft, maybe a week or two to refine that draft -- clearly not enough.

There are also other institution-specific issues (e.g., how to count the credits, etc., of transfer students coming from the more common semester system, etc.) . But simply from a learning standpoint, are there reasons to favor one calendar over the other?