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Re: Proposal to drop support for pointing to a specific DR

From: Phil Archer <parcher@icra.org>
Date: Thu, 08 May 2008 10:27:27 +0100
Message-ID: <4822C77F.7050609@icra.org>
To: Public POWDER <public-powderwg@w3.org>

The further implications of this - dropping support for linking directly 
to a specific DR rather and only talking in terms of linking to a POWDER 
document - is that the very confusing and potentially troublesome 
business of having ordered lists of DRs across multiple documents can be 
got rid of. Section 2.4.1 [1] suggests using dc:isPartOf and well, it 
just looks ugly. I don't think we lose anything, and gain a lot of 
clarity, if we say that ordered lists of DRs must be in a single document.

All of which means that we can drop the whole of section 2.4 and just 
have a note in the linkage section that allows one POWDER doc to point 
to another so that once you've found one POWDER doc, you can find other 
related ones - something I think Kai has mentioned a few times.

Unless someone screams, I'll do this in the version I'm editing now (it 
can always be put back).

Phil.


[1] http://www.w3.org/TR/2008/WD-powder-dr-20080317/#partOf

Phil Archer wrote:
> 
> We have a slight problem, but only a slight one.
> 
> In the current published version of the DR doc there's a section on 
> "Multiple DRs With Different Attribution" [1]. This suggests that you 
> can do this:
> 
> <dr xml:id="red">
>   <iriset>
>     <includehosts>example.com</includehosts>
>   </iriset>
> 
>   <descriptorset>
>     <palette:color>red</palette:color>
>   </descriptorset>
> </dr>
> 
> <dr ref="http://example.com/powder2.xml#square" />
> 
> i.e. link from a POWDER doc to a specific DR in another doc.
> 
> Well, you can in POWDER. The semantics here being that after you've 
> finished parsing the first DR, you might want to go and take a look at 
> http://example.com/powder2.xml#square. Fine... but it doesn't translate 
> exactly into POWDER-S. At least, not as we're now writing it following 
> the discussion over how to express the sub class relationship [2]. The 
> simpler way to assert the sub class, and in my view the more natural 
> way, is to do this:
> 
> <owl:Class rdf:about="#resourceset_1">
>   <rdfs:subClassOf rdf:ID="description_1"/>
> </owl:Class>
> 
> This has particular benefits when it comes to expressing ordered lists 
> in POWDER-S where it becomes a very elegant and simple way of excluding 
> IRI sets that should be excluded 'cos they're higher up the list (see 
> the Stasinos paper on this).
> 
> But... notice that the descriptor set and IRI set have their identifiers 
> and the bit of RDF/OWL here just adds to the information about 
> resourceset_1 - it has no identity of its own. Therefore, there is 
> nowhere to use the 'square' identifier that we had in the original 
> POWDER XML.
> 
> Does this matter?
> 
> What exactly should a processor do with the information that 'there's 
> another DR at http://example.com/powder2.xml#square ? Shouldn't it first 
> decide whether to trust it or not? If you go straight to the DR you 
> might skip the attribution information - which goes against the ethos 
> somewhat (and means a different processing model depending whether you 
> arrive at the DR with or without a fragment identifier). I think it 
> could be argued... OK, I will argue... that the better thing to do is to 
> link to the external document as a whole. One might think of it like this:
> 
> <attribution>
>   <maker ref="http://www.example.org/foaf.rdf#me" />
> </attribution>
> 
> <dr xml:id="red">
>   <iriset>
>     <includehosts>example.com</includehosts>
>   </iriset>
>   <descriptorset>
>     <palette:color>red</palette:color>
>   </descriptorset>
> </dr>
> 
> <seealso ref="http://example.com/powder2.xml" />
> 
> In POWDER-S that last element would become:
> 
> <rdf:Description rdf:about="">
>   <rdfs:seeAlso rdf:resource="http://example.com/powder2.xml
> </rdf:Description>
> 
> Which means, in POWDER-S, you may as well put it in what we think of as 
> the attribution block since the subject of the triple is the document 
> itself, as is the case for the foaf stuff etc.
> 
> I hope I'm making this clear although I fear I may not be :-(.
> 
> Basically, I'm arguing that we should just use an element called 
> <seealso /> to link from one POWDER doc to another and not worry about 
> linking to a specific DR.
> 
> Phil.
> 
> 
> [2] http://lists.w3.org/Archives/Public/public-powderwg/2008Apr/0034.html
> [1] http://www.w3.org/TR/2008/WD-powder-dr-20080317/#multiDRatt
> 
> 
Received on Thursday, 8 May 2008 09:28:05 GMT

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