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Ray, we had a lively back-and-forth conversation going on that has 
suddenly stopped, and I'm wondering what your thinking is at this point. 
I'm sure that Tom didn't intend to shut the conversation down, and much 
of what he says echoes what we were discussing prior to his reply.

Where do we go from here? Is there a resolution? Agreement? Further 
discussion?

Thanks,
kc

On 11/17/15 12:17 PM, Tom Johnson wrote:
> On Tue, 17 Nov 2015 09:40:38 -0500, Denenberg, Ray <[log in to unmask]> wrote:
>
>> Clearly there is confusion over "resource" - web resource, information
> resource, RDF resource. I'm not sure it's useful to sort through it all, as
> some of these definition have historical significance only.  So let's try to
> break this down without talking about resources.
>
>> An RDF property may be a datatype property or an object property. A
> datatype property takes a literal for its object (Quotes).  An object
> property takes an "individual" for its object (braces).   "Individual" as
> in, a member of an RDF class.  An individual always has an RDF description
> (or in your terminology, you can always make an RDF statement about it).
>
> It's unclear to me where any of this comes from. It isn't an accurate
> description of RDF or RDFS, which have only one type of property
> (rdf:Property). OWL does have DatatypeProperty and ObjectProperty classes,
> but they are subclasses of rdf:Property; other types of properties are
> allowed.
>
> Additionally, it is allowed, desirable, and common to link to resources on
> the web in Linked Data, even when they do not have RDF representations.
> Every item in DPLA, for instance has triples of the form:
>
>    :aggregation a ore:Aggregation ;
>       edm:isShownAt <http://example.com/some/item/page.html> .
>
>    <http://example.com/some/item/page.html> a edm:WebResource .
>
> Using a literal in place of that resource would be obfuscating and would
> prevent us and others from making additional assertions about it. Web pages,
> jpegs, ebooks, etc... *are* (or at least, can be) OWL individuals.
>
> What you refer to as an "RDF resource" is only one of the kinds of things we
> want to talk about, and while it's good practice to have RDF descriptions,
> there are cases where this isn't feasible or necessary (e.g. because someone
> else controls the server that hosts the web page you want to describe).
>
> I would also suggest using different terminology; as Karen has pointed out,
> "RDF resource" has a formal meaning within the specifications. A related
> concept that may interest you is "RDF source"[0], loosely: resources that
> provide an RDF Graph. This concept is used heavily in the recent Linked Data
> Platform spec[1].
>
> [0] http://www.w3.org/TR/rdf11-concepts/#dfn-rdf-source
> [1] http://www.w3.org/TR/ldp/#dfn-linked-data-platform-rdf-source
>
>
> Tom Johnson
> Metadata & Platform Architect
> Digital Public Library of America

-- 
Karen Coyle
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m: +1-510-435-8234
skype: kcoylenet/+1-510-984-3600