Discovery/notification

At Wednesday's conference call we talked briefly about discovery, which, in the annotation context, I would describe loosely as the capability for a client to discover annotations for a specified resource (more generally, to query those annotation based on search criteria).   I mentioned that without this capability, annotations are of no use to me, but I also noted that it is not my intent to impose on this group the burden to develop or specify querying mechanisms; I would like there to be a mechanism whereby when a resource is  annotated a notification can be sent to the owner of the resource. (And similarly, a notification when an annotation is deleted or updated.)  Such notification need not be mandated (the annotator is free to choose not to send the notification) and no burden is to be placed on the resource upon notification (the resource is free to ignore it).

Such a notification mechanism is, for me, sufficient to enable discovery and the remainder of the discovery process may remain out-of-scope.

I mentioned that I had previously submitted a number of use cases, some of which illustrate the discovery requirement, and I was asked to re-post the relevant cases. So here are two:


 *   Cover Art. A "Cover Art" annotation asserts that a particular image is cover art for a particular book or version of a book.  Thus the body is an image and the target is a resource description of a book (or particular version of the book).
 Use Case: Hennepin County Library acquires a copy of a new version of  Shakespeare's Macbeth. The library wishes to find cover art that it can use to advertise its copy. (Either there was no cover art supplied with the copy, or the cover art supplied was not deemed satisfactory.) There are dozens or perhaps hundreds of cover art images for Macbeth. For many of these images, someone (either the artist, or a third-party annotator) has created an annotation saying "this image is cover art for this version". The Library locates the RDF resource corresponding to its version of the book; it  can then search cover art Annotations of that resource and select one that it likes.
 *   Holdings.  A "Holding" annotation asserts that a particular library holds a copy of a particular item (e.g. book).  Thus the body is a structured description of the holding, including the holding library, its location, call number of the item, access conditions, etc.  The target is a resource description of the item.
 Use Case: Lucy is looking for a copy of the book Plum Island, by DeMille. She would like to find a local library that holds a copy, within her town of Independence Missouri. She searches by author/title and finds the resource description. She then searches for  Holding Annotations attached to the resource description, and discovers that Blue River Library has a copy, which she is able to borrow.

Ray