Re: Use-Cases and call for help to add descriptions and scenarios.

On 10/3/12 2:53 PM, Arnaud Le Hors wrote:
> IBM has been struggling with the concept of two way relationships such 
> as describes+describedby. While it's convenient to have two links so 
> you can navigate from one resource to the other in either direction, 
> maintaining those links adds a significant amount of pain and 
> constraints.
>
> This is clearly not the way the web of documents works. Anyone can add 
> links from their web page to other pages without expecting or 
> requiring reciprocity. This makes the web much more agile and 
> resilient. But when it comes to data people tend to expect reciprocity 
> and sometimes find unidirectional links unacceptable.
>
> I'd like to hear what people's experience has been on that front.

There is a big problem with RDF documents out in the wild re. Linked 
Data. A majority of these documents omit statements (triples) that 
include the URI denoting the actual description document.

Typical example. Given an RDF based Web document denoted by the URI/URL: 
<http://example.org/document/sample.rdf> . The content of this document 
would typically contain:

<#SomeSubjectURI> <#SomePredicateURI> <#SomeObjectURI> .

Omitting:

<#SomeSubjectURI> wdrs:describedby 
<http://example.org/document/sample.rdf> .
<#SomePredicateURI> wdrs:describedby 
<http://example.org/document/sample.rdf> .
<#SomeObjectURI> wdrs:describedby <http://example.org/document/sample.rdf> .

and/or:

<http://example.org/document/sample.rdf> foaf:topic <#SomeSubjectURI> .
<http://example.org/document/sample.rdf> foaf:topic <#SomePredicateURI> .
<http://example.org/document/sample.rdf> foaf:topic <#SomeObjectURI> .

Of course, it could be that at the time of document creation the docs 
actual URI/URL is unknown, that notwithstanding, the statements in said 
doc could take the form:

<#SomeSubjectURI> wdrs:describedby  <> .
<#SomePredicateURI> wdrs:describedby  <> .
<#SomeObjectURI> wdrs:describedby  <> .

and/or:

<> foaf:topic <#SomeSubjectURI> .
<> foaf:topic <#SomePredicateURI> .
<> foaf:topic <#SomePredicateURI> .


The obvious benefit here is that Linked Data's follow-your-nose pattern 
ends up with multiple commencement points that are easy to understand. 
For years, we've automatically (or via manually post-processing) added 
these triples to tons of RDF documents we've consumed.

RDF does stand for the Resource Description Framework. Ironically, a 
majority of RDF documents bear incomplete descriptions  :-)


Kingsley
> --
> Arnaud  Le Hors - Software Standards Architect - IBM Software Group
>
>
> Kingsley Idehen <kidehen@openlinksw.com> wrote on 10/03/2012 11:04:01 AM:
>
> > From: Kingsley Idehen <kidehen@openlinksw.com>
> > To: public-ldp-wg@w3.org,
> > Date: 10/03/2012 11:05 AM
> > Subject: Re: Use-Cases and call for help to add descriptions and 
> scenarios.
> >
> > On 10/3/12 1:41 PM, Wilde, Erik wrote:
> > > On 2012-10-03 8:39 , "Steve Battle" <steve.battle@sysemia.co.uk> 
> wrote:
> > >> For the scenario where the URIs do differ, do you have any 
> thoughts on
> > >> whether POWDER would be a good approach to making the 
> relationship between
> > >> the non-information and information resources explicit?
> > >> e.g. <http://example.com/people/alice> wdrs:describedby
> > >> <http://example.com/people/alice.rdf>
> > > i think this is exactly was POWDER's 'describedby' was created 
> for, and
> > > for making the reverse direction discoverable,
> > > http://tools.ietf.org/html/draft-wilde-describes-link-01proposes a
> > > 'describes' link relation type.
> > >
> > > cheers,
> > >
> > > dret.
> > >
> > >
> > >
> > >
> > 'describes' is the inverse of 'describedby'  which is semantically
> > equivalent to wdrs:describedby .
> >
> > Example:
> >
> > http://linkeddata.informatik.hu-berlin.de/uridbg/index.php?
> > url=http://dbpedia.org/page/Linked_data&acceptheader=&useragentheader=
> > -- URI Debugger output against DBpedia URI
> >
> >
> >
> > --
> >
> > Regards,
> >
> > Kingsley Idehen
> > Founder & CEO
> > OpenLink Software
> > Company Web: http://www.openlinksw.com <http://www.openlinksw.com/>
> > Personal Weblog: http://www.openlinksw.com/blog/~kidehen 
> <http://www.openlinksw.com/blog/%7Ekidehen>
> > Twitter/Identi.ca handle: @kidehen
> > Google+ Profile: https://plus.google.com/112399767740508618350/about
> > LinkedIn Profile: http://www.linkedin.com/in/kidehen
> >
> >
> >
> >
> >


-- 

Regards,

Kingsley Idehen	
Founder & CEO
OpenLink Software
Company Web: http://www.openlinksw.com
Personal Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca handle: @kidehen
Google+ Profile: https://plus.google.com/112399767740508618350/about
LinkedIn Profile: http://www.linkedin.com/in/kidehen