Annotation creation and updates

Dear all,
I am currently developing the Annotopia Open Annotation server [1][2][3]
and there are a few topics that I believe would be wise to discuss in the
mailing list in order to collect some additional feedback.

I will start with one topic: keeping track of annotation creation and
update (date/agent).

I collected some non conclusive thoughts here:
http://hcklab.blogspot.com/2014/04/annotopia-creationupdates-with-open.html

No versioning for now. If that is of interest, months ago, I wrote some
thoughts here: http://www.w3.org/community/openannotation/wiki/Versioning

In short, I am currently thinking of using PAV [4] with something like this:

{
    "@id" : "http://host/s/annotation/830ED7EE-BF7B-4A18-8AE1-A9AF96AC135B",
    "@type" : "oa:Annotation",
    "annotatedAt" : "2014-02-17T09:46:11EST",
    "annotatedBy" : {
      "@id" : "http://orcid.org/0000-0002-5156-2703",
      "@type" : "foaf:Person",
      "name" : "Paolo Ciccarese"
    },
    "pav:createdOn" : "2014-02-17T09:48:11EST",
    "pav:createdBy" : {
      "@id" : "http://orcid.org/0000-0002-5156-2703",
      "@type" : "foaf:Person",
      "name" : "Paolo Ciccarese"
    },
    "pav:lastUpdateOn" : "2014-03-11T11:46:11EST",
    "pav:lastUpdateBy" : {
      "@id" : "http://example.org/johndoe",
      "@type" : "foaf:Person",
      "name" : "John Doe"
    }
...
}

Where:
(i) 'createdOn/createdBy' for the original creation on the (Annotopia)
server
(ii) 'lastUpdateOn/lastUpdateBy' for the last update on the (Annotopia)
server

Question is: what is 'annotatedAt' going to indicate once the annotation
has been updated? The original creation or the latest update? In fact, some
application will understand only the 'annotatedAt' property.

Another option I have, to keep the actual annotation pure OA, is to collect
the additional provenance data in a separate provenance graph that can be
provided on demand by who can understand it.

Any thoughts?

Best,
Paolo

[1] GitHub (Code/wiki): https://github.com/Annotopia/AtSmartStorage
[2] Slides (living documentation):
http://www.slideshare.net/paolociccarese/annotopia-overview-by-paolo-ciccarese
[3] Talk @ 'I Annotate 2014' https://www.youtube.com/watch?v=UGvUbFv0Zl8
[4] PAV: http://www.jbiomedsem.com/content/4/1/37

-- 
Dr. Paolo Ciccarese
Assistant Professor of Neurology, Harvard Medical School
Assistant in Neuroscience, Massachusetts General Hospital
Senior Information Scientist, MGH Biomedical Informatics Core