Thanks for that information, Dan.  Two follow-up questions:

When I first click on a shared link – before I open the document – it still says “Untitled document” – so if I’m trying to see what dataset I’m opening, I actually have to open it, rather than just clicking on the link for a preview.  Any chance that can be changed?

I was confused about your answer to my last question: I thought that a student could just save a shared file to Google Drive (using Save) and the teacher could look at it – rather than having to create another shared file.  Am I wrong about that?