Re: Class of an annotation body

Hi Ray,

The issue is mostly one of provenance and graph boundaries, so falls under
the same discussion as named graphs for bodies discussion that we had on a
recent call.

There are two main options for body resources with structure:

1.  The body is an external or embedded document containing structured
data, or a named graph containing triples, such that the document/graph can
be maintained and referred to separately from the annotation.  For example,
a review in XML that had fields with number of stars, text of the review
and so on fills the same role as a named graph containing the same
information with triples instead of XML elements.

2.  The triples are part of the annotation graph, and thus cannot be
referred to separately.  Consider as a parallel, the body-as-string versus
body-as-resource distinction.  This is the body-as-string case, where there
isn't a distinct resource to refer to... there are just triples in the
annotation.  For example, the body could be a blank node with numberOfStars
and rdf:value predicates.  These assertions are made by the agent that
asserts the annotation, which may not be correct ... but also may not be a
concern, depending on the use case.  For the general case, and hence for
interoperability, the boundary of the body is another challenge.  The set
of resources that are needed to make a useful body is arbitrary and use
case dependent.  For dedicated systems this may not be an issue, but if you
imported the annotation content into another system, it's unlikely that it
would know which triples should be included and which not.

Others please do weigh in :)

Rob



On Mon, Mar 9, 2015 at 12:05 PM, Denenberg, Ray <rden@loc.gov> wrote:

> In the OA data model, there is no general RDF Class defined for the body.
> But that doesn’t mean that the body cannot have an RDF class, for certain
> types of annotations.  For example, for  a tag, the body has class oa:Tag
> and for a semantic tag, oa:SemanticTag.   (Those are the only two I can
> think of from the model, maybe there are others I missed.)
>
> There is at least one use case that calls for a structured body and thus
> an RDF Class (Structured Review:
> http://www.w3.org/TR/dpub-annotation-uc/#comment-on-publication-title).
>  And it also seems that there is a certain amount of hand-waving that
> suggests that bodies are going to need to be structured in many cases but I
> don’t think we have had direct discussion of this.
>
> I am in the process of developing a use case along these lines and would
> like opinions on whether this approach is seen to be legitimate or frowned
> upon – annotations where the body has properties - because there was
> discussion of this in BIBFRAME and it seemed to cause controversy.
>
> Ray
>
>
>
>
>



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