RE: Re: Profiles in Linked Data

Kingsley,

On Thursday, May 07, 2015 7:59 PM, Kingsley Idehen wrote:

[...]
> >> The document content retrieved is in RDF-Turtle form, and by way of
> "profile"
> >> relation a user agent should assume that it adheres to the principles
> outlined by
> >> the concept identified by
> <http://www.w3.org/DesignIssues/LinkedData#this> .

> > Term clarification: My notion of profile is what the Dublin Core community
> calls an Application Profile [1], in this particular case it's a description telling a
> consumer what (RDF) classes and properties are used to describe a resource
> [2], similar to the RDF data shapes [3]. I'm not sure the linked data principles
> count as such a profile.
> 
> Of course they do, otherwise the document containing the meme wouldn't
> exist.

OK, now I think I understand your argument. By referencing the LD meme [1] as a profile you're essentially making the statement that you want to access the resource in a fashion consistent with that architectural principle. Right?

> RDF mandates the use of IRIs for entity denotation. That doesn't imply
> HTTP URIs. Out in the wild, there are lots of RDF documents that don't
> adhere to the principles outlined in TimBL's meme. That's why he had to
> craft the meme.
> 
> Remember, XML basically blurred the lines of what an HTTP URI is about
> by its proliferation of HTTP URIs that didn't resolve i.e., you had
> denotation without connotation (what you get with identification by way
> of name->description-document based indirection).

If two agents can agree on common URIs for the same entities we can at least figure out that two documents served by those talk about the same thing just by comparing the URIs, even if we as a third party don't know exactly what they denote (since there is no description, because the two original agents negotiated that through email). 

> You can also look at the HTTP URI issue from the REST perspective, in
> that worldview HTTP URIs only identify Web Resources i.e., documents.
> Net effect, the fundamental duality of an HTTP URI is again blurred, and
> the basis for endless debates.
> 
> Thus, a "profile" relation that is resolved (via our heads) to a
> document [written in English] in an IANA hosted doc on the Web could
> serve as a bridge across these world views, sorta.

What would be the contents of that IANA document?

> >
> >> Bearing in mind:
> >>
> >> <http://www.w3.org/DesignIssues/LinkedData#this>
> >> is schema:about of <http://www.w3.org/DesignIssues/LinkedData> .
> >>
> >> OR (in purer Turtle):
> >>
> >> <http://www.w3.org/DesignIssues/LinkedData>
> >> schema:about <http://www.w3.org/DesignIssues/LinkedData#this> .
> > I agree with the statements but cannot quite follow what you want to tell me.
> 
> Explained using nanotation [1][2] i.e. actual RDF-Turtle notation based
> digital sentences that can be used to create structured data islands,
> that conform with Linked Open Data principles, wherever you can insert
> "text/plain" content:

OK, I got the idea.

[...]

> >> I am walking through this piecemeal, because I've circled this wagon a few
> >> times in other quarters (typically in forums such as LDP [most recent
> >> occurrence]) [1].
> >>
> >> CON:
> >> Basically, if what I've outlined is accurate, we've ended up adding a signal
> (via
> >> HTTP request and response metadata) to indicate what's implicit re.,
> AWWW
> >> (Architecture of the World Wide Web) i.e., that HTTP URIs are Name that
> >> resolve to descriptions of what they denote (i.e., an HTTP URI has a
> denotation
> >> and connotation duality that enables them function as Terms).
> >>
> >> PRO:
> >> Anyway, countering myself [as I type], I've also realized that when the
> Content-
> >> Type is one of those associated with the RDF Language, we could look to this
> >> "profile" relation as a mechanism for a user agent to signal that the RDF
> >> Language based content requested has to conform to the principles
> associated
> >> with the concept identified by
> >> <http://www.w3.org/DesignIssues/LinkedData#this>. And likewise, a server
> can
> >> return content also using "profile" to indicate that said RDF content is in
> RDF-
> >> Turtle form, and conforms to the principles associated with the concept
> >> identified by <http://www.w3.org/DesignIssues/LinkedData#this>.
> > Well, no. This is not what I try to achieve. It's really about negotiating
> application profiles/data shapes.
> 
> Okay, so please paste a representation of the profile you have in mind.
> Note, I am not asking for English prose here. I am requesting data
> representation that can be processed by both humans (not solely for an
> English Language speaker) and machines [that understand entity
> relationships and relation semantics].

I don't have one ready. Essentially my notion of an RDF profile would be the same as what the data shapes WG is constructing: A description of what classes, properties and datatypes (and how they are interconnected) a representation will consist of. The reason I started by using the word "profile" is because of the similarities to profiles as described in ยง3 of RFC 6906 [2]:

[[
For the purpose of this specification, a profile can be
   described as additional semantics that can be used to process a
   resource representation, such as constraints, conventions,
   extensions, or any other aspects that do not alter the basic media
   type semantics.
[...]
While this specification
   associates profiles with resource representations, creators and users
   of profiles MAY define and manage them in a way that allows them to
   be used across media types; thus, they could be associated with a
   resource, independent of their representations (i.e., using the same
   profile URI for different media types).
]]

[1] http://www.w3.org/DesignIssues/LinkedData#this

[2] http://tools.ietf.org/html/rfc6906#section-3


Best,

Lars

As said: I'm just trying to understand...

Received on Friday, 8 May 2015 10:05:19 UTC