I think I may have put the cart ahead of the horse and want to pick everyone’s brains regarding best practices.
I had each of my students add a series of historical images from the local preservation society to our site. Would these be better organized as collections or an exhibit?
Since we’re talking about students, the primary consideration is certainly the pedagogical goals. So, what I say should be checked against that.
Collections pretty much group items together around a theme or idea. As such, it’s an item-specific thing, which will emphasize the items and very close analysis of them. (Note that items can only belong to one collection in the default Omeka system.)
Exhibits are much more about providing a narrative context around items. So, if the students will be doing work interpreting the items and putting them in a broader context, that sounds like an exhibit.
We might be able to have better guidance with more info about the course and its goals.
While in general, I follow the advice that Patrick laid out, a recent site that I built had collections and exhibits running in parallel, So while the exhibit showed featured items from a specific collection, they also wanted a button on the exhibit that said “Show other items in the collection” which would take you to the collection list of items. In effect, an exhibit was just a special, more detailed discussion about a collection.
But items in different collections can appear in one or more exhibits and exhibits don’t have to be restricted to a single collection. I tend to believe that it is almost always best to organize items into collections. Then you can decide how you want items and collections to be used by exhibits.
While I’m still learning about best practices myself, my understanding is that collections should reflect a group of items in its original state/order. An exhibit is curatorial in nature, and so may include items from multiple collections.
Here’s a decent overview of the traditional approach to organizing an archive of material: https://peelarchivesblog.com/2015/08/26/how-do-archivists-organize-collections/