Thank you for your reply, Barry. I'm sure that is good advice for projects where the slide shows are the primary objective, but in my case archiving, researching, cataloging and sharing historical photographs is the primary objectives and creating slide shows is only one way of sharing images.
Organizing the images on disk based on the slide shows in which they are contained is not appropriate and is also not practical because the same image will often be included in multiple shows.
The metadata for images changes over time as research identifies more information about the photos and the people and places in them and the dates they were probably taken. It would be difficult to keep multiple copies of an image up to date if they are scattered around in several different locations.
We also annotate some images identifying the people in them, etc. Changing those annotations when new information is discovered would entail copying the new image to multiple locations.
We create ordered image sets in our software for multiple purposes, only one of which is creating slide shows with P2E. It is a duplication of effort to then have to regenerate each set in P2E.
...Jim