Re: Data Model Assumptions

On Tue, Aug 18, 2015 at 10:01 AM, Doug Schepers <schepers@w3.org> wrote:

> This is actually why I raised the issue of putting Motivation directly on
> the Body; it explains what role each Body plays in the whole Annotation
> (though not necessarily what the relationship of each Body is to each
> Target, for example).
>
> These entailments are where Rob and I might differ, BTW; he said [1], “The
> role of the resource in the annotation is not a property of the resource,
> it is a relationship between the Annotation and the Resource.”
>
> I might be misunderstanding him, but if "Resource" means a Body (in this
> case), then putting the role/motivation in the Body seems like the most
> straightforward way to describe the relationship of that Resource to the
> Annotation.
>

Yes, in this case we're talking about the body, but the same applies to any
other resource. (Intentionally overlooking the non-resource literal
bodies).  I'll try to explain further why I strongly believe this to be
true, regardless of linked data or RDF.

The role of the body in the annotation is not a property of the body,
because it's only true for the particular annotation, not generally.

It is not a property of a video, that someone has used it in a certain way,
any more than that it is a property of a web page for which browser some
user is looking at it with.  You cannot set page.browser = chrome because
someone else can just as reasonably view it in firefox.  Instead the person
views-in-chrome the page.  Viewing-In is a relationship between the user,
the page and the browser.  It would have properties like when it was viewed.

You cannot set video.role = commenting because someone can just as
reasonably use that same video in a different role, such as questioning or
replying.  Instead, the annotation uses-as-a-comment the video.

To avoid annotation.uses_as_a_comment = video, we have an extensible set of
motivations and a single property of "body":

annotation.body = video


But remember we can't say video.role = commenting as it's _specific_ to the
annotation.  Thus we introduce a level of indirection for the body:

annotation.body.role = commenting
annotation.body.source = video

And that is the specific resource.  It holds properties that are specific
to the annotation about the annotation's use of the video.  Similarly, it's
not a property of the video that the annotation only needs the first 60
seconds of it.  Instead we have a selector on the specific resource:

annotation.body.selector.value = "t:0,60"

It's not a property of the HTML page that the annotation needs a specific
segment of it. It's not a property of the page that the comment is about a
representation of it at a certain time. It's not a property of the page
that the annotation creator wants the region highlighted in green rather
than red.  It's not a property of the page that the annotation uses it as a
comment, rather than a question.

Maybe that makes it clearer, I hope so!

Rob