Re: Submodules or similar for exercise/exam management

Jonathan Nieder wrote:

Indeed.

I tried to not go too deeply into the status quo to keep the original mail short, but if you really care, here goes (there's nothing else below this point so you can also stop reading):

In my own group (theoretical CS), we have a Big Ugly SVN repository with a directory per class taught, with subdirectories for the exercises of every year. Either at the beginning or during the year, we copy the previous exercises and solutions to a new directory and modify/fix them to taste. Similar for exams.

This works reasonably well because all our lectures are on mostly disjoint topics, so we rarely share anything between them. The directories act more as a "tag" of the old version than anything else, and also help lazy users find the old version without talking to SVN. Converting it to git would be fairly trivial since the usage maps straight to lecture-projects with tags at the end of every semester, but largely due to inertia nobody wants to do it.

The statistics institute where my colleague works is different in two major respects.

First, they do not currently have any kind of enforced versioning. There apparently are a bunch of directories along similar lines as the above, but they live on a big shared NFS and thus it's easy to lose existing state simply by overwriting it. This is good for the purposes of this discussion because we can weigh the pain of living with the existing solution against the pain of using the new solution ;-)

More importantly, and this spawned my question, they have a lot more overlaps between lectures. (I assume this is because they give statistics courses at various levels of difficulty to various other departments/subjects of study, but I don't really know.)

Thus it often happens that an exercise is copied from lecture A to B, then later some mistake is fixed in A and the fix does not propagate. Worse, for whatever reason they might later copy back the exercise from B to A and thus have a regression.

Handling at least this case sanely would already be good. The requirement that Junio criticized above is geared not towards sanity of the use-case, but towards not making adoption so complicated as to make it impossible.

It is true that in cases where submodules really pay off, such exercises (or perhaps more realistically, guides and lecture notes) being customized slightly for each course. This would need branches. For now I am putting this case a bit into the background since it can be solved by working on such documents in a separate repo, splitting the customizations into branches and merging the fixes from the main copy; and then just binding the appropriate version as a sub-repo.

And yes, this would in theory also go for books as you described:

Though I wonder how that pans out in practice since it is rarely possible to just "drop in" a chapter without rewriting significant parts of it to match the rest of the book.