Re: [model] Clarifying annotation architecture

Hi Ivan,

> I am not sure why a URI must be assigned to a blank node body. However, it
>> indeed it must, then (just as in any other RDF environment) I believe it is
>> a requirement that URI-s assigned to a body must be unique.
>
>
> It doesn't have to be, but some systems will just do it for you.  The best
> practices of linked data are to avoid blank nodes, after all.
>
> Yeah, well, I do not think we should be religious about it. In my view,
> using blank nodes for the situations we are discussing here is perfectly
> fine.
>

Indeed, but we shouldn't prevent other people from being religious about it
:)

The use case I gave earlier was if you want to annotate the body and
> particularly if you're using a selector, it needs a URI to be the target of
> the second annotation.  You can't target the annotation and mean the body,
> as it would be ambiguous in the case we're discussing of multiple bodies.
>
> I am lost. I think Tim's example was for the resources used as an
> encapsulation for the body and a motivation. That one does not really need
> its own URI. That is where blank nodes are perfectly fine.
>

They're fine until someone wants to reuse it when it does get its own URI.
Blank nodes are still resources.

I do not understand what you mean here. My only comment was to say is that
> if the system chooses to provide a URI to blank nodes (ie, it skolemizes
> the blank nodes), we can safely assume and even require that the resulting
> URI-s will be different for different blank nodes.
>

They'll be different URIs, sure, but that doesn't mean that they're
reusable.  If the motivation is associated with the body directly, then it
cannot be reused in another annotation. You couldn't target the body to
comment about a spelling mistake. There would be different models for blank
node resources and resources where those blank nodes have been assigned a
URI.  That then means understanding why there are two models... and we're
back to the same situation... except it's more likely that people will do
it incorrectly by inferring from the blank node case that the same will
work with URIs.

Rob


-- 
Rob Sanderson
Information Standards Advocate
Digital Library Systems and Services
Stanford, CA 94305