Re: Annotations and the Graph

Hi Randall,

Can you explain more about the use case for this?

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.

(tentatively -1)

Regards,

Jacob


_____________________________________________________
Jacob Jett
Research Assistant
Center for Informatics Research in Science and Scholarship
The Graduate School of Library and Information Science
University of Illinois at Urbana-Champaign
501 E. Daniel Street, MC-493, Champaign, IL 61820-6211 USA
(217) 244-2164
jjett2@illinois.edu

On Tue, Oct 27, 2015 at 3:16 PM, Randall Leeds <randall@bleeds.info> wrote:

> I realize I sent this without finishing with a concrete proposal, so here
> it is, with maximal backward compatibility (though I would consider more
> aggressive changes, too).
>
> Make oa:Annotation a subclass of rdfs:Statement. Without loss of
> generality, make oa:hasTarget and oa:hasBody sub-properties of rdfs:subject
> and rdfs:object. Rename the motivations so that they clearly describe the
> relationships between subject and object.
>
> If we would like to maintain some of the same multiplicity behavior, make
> it clear than any number of subjects and objects can be related by one
> predicate (or maybe more, but that seems dubiously useful).
>
> On Tue, Oct 27, 2015 at 1:11 PM Randall Leeds <randall@bleeds.info> wrote:
>
>> My attraction to annotation is the promise of containers for referencing
>> and relating content.
>>
>> The SpecificResource and its associated Selector classes accomplish the
>> task of fixing references to content (not just URLs).
>>
>> Motivations accomplish the relating. The roles proposal expresses a
>> desire to do so even more granularly.
>>
>> Motivations (and roles) makes the relation between body and target into
>> an object related to the annotation (or body). This succeeds in avoiding
>> publishing statements that explicitly involve the body and target as
>> subject and object of a statement, but leaves the relation between the body
>> and target to inference.
>>
>> Possibly one of the most important semantic statements the annotation
>> could convey is not even in the graph!
>>
>> That is all fine and well motivated (ha!), but there already exists the
>> RDF Schema reification vocabulary for conveying triples that are, for
>> whatever reason, kept initially out of the graph.
>>
>> Consider a typical annotation use case, using rdfs:Statement,
>> oa:SpecificResource and schema:Comment:
>> http://json-ld.org/playground/#/gist/0185862e6812fd5a908e
>>
>> Here, the only Web Annotation Data Model classes I've used are
>> SpecificResource and TextQuoteSelector. I chose "target" and "body" for
>> mapping context terms to highlight the similarity to our typical examples.
>>
>> None of this is to argue that the Web Annotations Data Model needs to
>> constrain its vocabulary more. It's perfectly fine and great to instantiate
>> new vocabulary terms that are identical or similar to terms in existing
>> vocabularies like schema.org and fix them within a W3C spec.
>>
>> For the extremely commonplace usage of annotation as targeted commenting,
>> putting <article, comment, body> into the graph would seem to be the
>> simplest thing.
>>
>> I would like to avoid querying for comments on this article PLUS
>> annotations with the commenting motivation that have this article as their
>> target or the source of their specific target. Wow, that second part seems
>> needlessly complex compared to the first, doesn't it?
>>
>> To remedy this, we could be more careful in defining our motivation terms
>> as rdf:Property instances that are meant to relate the bodies and targets
>> directly. The annotation is either a sub-class of rdfs:Statement or perhaps
>> it's a resource with a collection of one or more rdfs:Statement.
>>
>> I could ingest annotations and reify the new triples they describe. I
>> could keep independent datasets, quads, named graphs, etc according to the
>> the non-Statement metadata the Annotation bears in order to keep
>> collections separate and non-conflicting, if I care to. Then I could make
>> straightforward queries.
>>
>> Right now we can't do this because "oa:commenting" is not
>> "oa:isCommentOn" and we don't reify <body, motivation, target> at all. We
>> are really unclear about what the relationship is between bodies and
>> targets, even in the role proposal.
>>
>> We are describing the annotation rather than using the annotation as a
>> vehicle to describe the world with attribution.
>>
>