Re: Annotations and the Graph

Jacob, is there any chance you could explain why you think my proposal
"breaks reasoners based on OWL"?

On Tue, Oct 27, 2015 at 4:13 PM Randall Leeds <randall@bleeds.info> wrote:

> On Tue, Oct 27, 2015 at 3:49 PM Jacob Jett <jjett2@illinois.edu> wrote:
>
>> Hi Randall,
>>
>> Can you explain more about the use case for this?
>>
>
> Sure.
>
>
>>
>> I think quite possibly that this proposal might result in a model that
>> breaks reasoners based on OWL. I remember reification being discussed at
>> one of the early OAC meetings and as I recall the models avoidance of
>> reification and scoping the relationship between the body and target is on
>> purpose. Perhaps Rob or Tim might recall why this was avoided but its not
>> clear to me if your proposal does not in fact make the standard unusable
>> for anyone employing reasoners, more or less defeating its semantic web
>> purposes.
>>
>> It blurs the line between semantics specific to the annotation model and
>> those specific to RDF.
>>
>>
> I thought I was pretty clear about the use case, but I'll try again.
>
> The use case is representing and querying annotations in a consistent and
> straightforward way.
>
> If a publisher posts an article (schema:Article) and its comments
> (schema:Comment) it relates them with a simple predicate (schema:comment).
>
> As an independent reader who wants to make my own comments, not
> necessarily involving the commenting system that the publisher has blessed,
> I want to use the same pattern.
>
> I want to take N repositories and query them for (Article, comment, ?) and
> get back all those objects which are comments on the article.
>
> Contrary to your concern, I was actually under the impression that my
> proposal makes things easier, not harder, for reasoners.
>
> Unless of course you are using "easier" to mean it's easier to ignore
> something than to try to derive meaning from it.
>
> One would think, I hope, that an oa:commenting annotation means that the
> body is a comment on the target.
>
> In order to reason that out, one needs to express that <the property chain
> that traverses the inverse of hasBody, through an an Annotation resource
> with the motivation oa:commenting, to the object of its hasTarget> implies
> a <comment> relationship between the two.
>
> The only complication my proposal presents to reasoners is that *only if
> they want to instantiate the triples described by the annotation* they will
> have to either namespace (named graphs, quads) the triples or deal with the
> fact that they are reasoning on this user data, which may be conflicting or
> inconsistent if it's not validated and trusted.
>
> That's data life, though. Validate and trust or quarantine and contain.
>
> Hoisting the predicate onto the annotation as a motivation seems to be
> serving the same purpose as RDFS reification: express the whole triple as a
> resource that can carry metadata, such as additional provenance
> information. That's similar also to use cases for a named graph.
>
> It could be that I'm misunderstanding something fundamental about named
> graphs or RDF. I'm especially curious to hear whether there are reasons why
> RDFS reification was considered and rejected.
>
>