Re: [SKOS] "SKOS RDF schema"

Sorry for the loose wording. My last sentence below should be read as supporting the global multiview disabling that you've proposed!

Antoine

> 
> - about the http://www.w3.org/TR/2009/PR-skos-reference-2009XXXX/skos 
> "generic document", I am quite puzzled. We say nothing about it in the 
> spec, it is not needed for content negociation as far as I understand, 
> and yet it exists :-) If it is a mere accident, is there a way to hide 
> it well under the carpet, or even turning off the multiviews feature 
> that leads to such a behavior?
> 
> Cheers,
> 
> Antoine
> 
> 
>> hi tom,
>>
>> i'd be happy with the following setup for PR, based on sticking close
>> to established practice e.g. OWL and on making the least change to our
>> own practices so far, although i'm happy to consider alternatives if
>> anyone has a better idea...
>>
>>
>> == SKOS ==
>>
>> we publish a "SKOS Namespace Document HTML Variant", at a url like:
>>
>> [a] http://www.w3.org/TR/2009/PR-skos-reference-2009XXXX/skos.html
>>
>> we publish a "SKOS Namespace Document RDF/XML Variant", at a url like:
>>
>> [b] http://www.w3.org/TR/2009/PR-skos-reference-2009XXXX/skos.rdf
>>
>> we publish a "SKOS RDF Schema (OWL 1 DL Sub-set)" at a url like:
>>
>> [c] http://www.w3.org/TR/2009/PR-skos-reference-2009XXXX/skos-owl1-dl.rdf
>>  
>> we make sure [a] has links directly to [b] and [c].
>>
>> in an appendix to the SKOS Reference, we state that the document at
>> [b] should be considered to be a part of the SKOS Reference, and hence
>> a part of the Recommendation. the appendix also states that [b] is a
>> normative subset of the SKOS data model.
>>
>> in a separate appendix, we do the same for [c] (i.e. state that it is
>> a part of the Recommendation, and that it is a normative subset of the
>> SKOS data model).
>>
>> we *do not* include the rdf/xml content of [b] or [c] explicitly in
>> these appendices, unless absolutely necessary to confer recommendation
>> status to the rdf/xml content. (it seems a bit crazy to do what owl 1
>> did and include the content of [b] or [c] explicitly in appendices to
>> the skos reference, and hence duplicate the rdf/xml content in two
>> places ... although if this is the only way we could resolve the
>> status issue, i could live with it.)
>>
>> we do recipe 3 redirects from <http://www.w3.org/2004/02/skos/core>
>> ("SKOS Vocabulary Namespace URI") to [a] and [b].
>>
>> we redirect from <http://www.w3.org/2004/02/skos/core.rdf> ("Latest
>> SKOS Namespace Document RDF/XML Variant") to [b]. this link is just a
>> convenience shortcut for developers, we mention it on the SKOS web
>> site but we otherwise don't include it in formal documentation.
>>
>> because of the way that [a] and [b] are published on an apache server
>> with multiviews enabled, there is also another url:
>>
>> <http://www.w3.org/TR/2009/PR-skos-reference-2009XXXX/skos>
>>
>> which is effectively a "generic document", but this is accidental and
>> not by design. If we need to refer to this in discussion, we could
>> call it the "SKOS Generic Namespace Document", but it is probably
>> better not to mention this link anywhere either in formal
>> documentation or on the web site, as it may cause confusion.
>>
>> alternatively, we disable multiviews for the entire directory, and so
>> the URI above will 404. this might be safer, and would certainly avoid
>> confusion over what cool URI pattern we're doing.
>>
>> a second alternative would be to switch from doing recipe 3 redirects
>> to doing 303 redirects to one generic document (see
>> <http://www.w3.org/TR/cooluris/#r303gendocument>), but it's a bit late
>> in the game to switch our practices like this, and would require some
>> testing and a rethink of inter-document links.
>>
>>
>> == SKOS XL ==
>>
>> we publish a "SKOS XL Namespace Document HTML Variant", at a url like:
>>
>> [d] http://www.w3.org/TR/2009/PR-skos-reference-2009XXXX/skos-xl.html
>>
>> we publish a "SKOS XL Namespace Document RDF/XML Variant", at a url like:
>>
>> [e] http://www.w3.org/TR/2009/PR-skos-reference-2009XXXX/skos-xl.rdf
>>
>> we publish a "SKOS XL RDF Schema (OWL 1 DL Sub-set)" at a url like:
>>
>> [f] 
>> http://www.w3.org/TR/2009/PR-skos-reference-2009XXXX/skos-xl-owl1-dl.rdf
>>
>> which imports [c] instead of <http://www.w3.org/2004/02/skos/core> but
>> is otherwise the same as [e].
>>
>> we make sure [d] links directly to [e] and [f].
>>
>> in an appendix to the SKOS Reference, we state that the document at
>> [e] should be considered to be a part of the SKOS Reference, and hence
>> a part of the Recommendation. in a separate appendix, we do the same
>> for [f]. we *do not* include the rdf/xml content of [e] or [f]
>> explicitly in these appendices.
>>
>> we do recipe 3 redirects from <http://www.w3.org/2008/05/skos-xl>
>> ("SKOS XL Vocabulary Namespace URI") to [d] and [e].
>>
>> we redirect from <http://www.w3.org/2008/05/skos-xl.rdf> ("Latest
>> SKOS XL Namespace Document RDF/XML Variant") to [b]. this link is just a
>> convenience for developers, we mention it on the SKOS web site but we
>> otherwise don't include it in formal documentation.
>>
>> because of the way that [d] and [e] are published on an apache server
>> with multiviews enabled, there is also another url:
>>
>> <http://www.w3.org/TR/2009/PR-skos-reference-2009XXXX/skos-xl>
>>
>> which is effectively a "generic document", but this is accidental and
>> not by design. If we need to refer to this in discussion, we could
>> call it the "SKOS XL Generic Namespace Document", but it is probably
>> better not to mention this link anywhere either in formal
>> documentation or on the web site, as it may cause confusion.
>>
>> alternatively, we disable multiviews for the entire directory, and so
>> the URI above will 404.
>>
>> ...
>>
>> how does that all sound?
>>
>> tom suggests combining SKOS and SKOS XL namespace documents into a
>> single document, but i would rather keep them separate, mainly because
>> having them separate reinforces the fact that XL is an optional
>> extension to SKOS, and means that people coming first to SKOS don't
>> have to deal initially with the extra layer of complexity.
>>
>> cheers,
>>
>> alistair
>>
>>
>>
>> On Mon, Apr 06, 2009 at 07:34:33PM +0200, Thomas Baker wrote:
>>> Dear all,
>>>
>>> I'm looking at [1], also known as [2].
>>>
>>> [1] http://www.w3.org/TR/2009/CR-skos-reference-20090317/skos.html
>>> [2] http://www.w3.org/TR/2009/CR-skos-reference-20090317/skos
>>>
>>> This document calls itself "SKOS Simple Knowledge
>>> Organization System RDF Schema".
>>> One obvious problem is that the document is clearly an HTML
>>> page and not an RDF schema. It may seem obvious to us that it
>>> is really _about_ the RDF schema, but I can well imagine this
>>> causing some confusion.
>>>
>>> In the section of that document labeled "SKOS RDF Schema", then,
>>> there is a link labeled "SKOS RDF Schema" which points to
>>>
>>> [3] http://www.w3.org/2004/02/skos/core
>>>
>>> which however -- since I am reading it in a browser --
>>> content-negotiates back to [1]!
>>> However, the section does provide an additional link directly
>>> to the schema itself ("download the RDF schema without content
>>> negotiation") [4].
>>>
>>> [4] http://www.w3.org/2004/02/skos/core.rdf
>>>
>>> Given the title and introduction, then, the reader does not
>>> necessarily expect to find the _contents_ of the RDF schema by
>>> scrolling down one screen.
>>>
>>> I find this all delightfully confusing... :-)
>>>
>>> Some issues and suggestions for discussion:
>>>
>>> -- Maybe call the Web document [1-2] "Contents of the RDF    schema 
>>> for Simple Knowledge Organization System (SKOS)"    or "Expressing 
>>> SKOS in RDF" - in effect, anything but
>>>    "SKOS RDF schema" :-)
>>>
>>> -- There should be a link labeled "SKOS RDF schema", but it    should 
>>> link to [4] directly, not via content negotiation from
>>>    [3].  The surrounding text, however, should describe the    
>>> content negotiation mechanism clearly.
>>>
>>> -- Status of the document [1-2]: I'm not sure we have properly
>>>    resolved this question. I think it would help the reader if
>>>    this document describes itself as a readable ready-reference
>>>    page which excerpts the contents of the RDF schema for SKOS,
>>>    and that the RDF schema for SKOS is itself a formalisation
>>>    of a subset of the semantic conditions described in SKOS
>>>    Reference, and that the SKOS Reference has the status of W3C
>>>    [Candidate] Recommendation.
>>>
>>>    Like the OWL ontology [5], the RDF schema for SKOS does not
>>>    assert any status for itself, though in the case of OWL,
>>>    the contents of the schema are replicated in an appendix to
>>>    the Recommendation document [6], arguably conferring on the
>>>    schema itself a status of Recommendation, assuming it merely
>>>    replicates the text in the appendix.
>>>
>>>    [5] http://www.w3.org/2002/07/owl
>>>    [6] http://www.w3.org/TR/owl-ref/#appB
>>>
>>>    This text provides an opportunity to clarify that the SKOS
>>>    Reference is the [Candidate] Recommendation and that [1],
>>>    [2], and [4] are all excerpts of that Recommendation.
>>>    (The text should point out that it is not possible to
>>>    express all of the statements of the SKOS data model as RDF
>>>    triples and thus the schema forms a "normative subset" of the
>>>    specification.)
>>>
>>> -- I'm wondering if this document [1-2] might be a good    place to 
>>> introduce and link any DL versions of SKOS as per Sean's
>>>    discussion in [7].  The document could briefly explain the need    
>>> to have a DL ontology in some contexts, describe the algorithm
>>>    by which some of the axioms in [4] are "thrown away" (or filtered
>>>    out).  In a way, the DL schema is arguably just another subset
>>>    of the semantic conditions described SKOS Reference, albeit a    
>>> deliberately lossy one.  Grouping points to the RDF, HTML, and DL    
>>> excerpts together in one document would be helpful; and where else    
>>> to do that but in this document [1-2]?  (This assumes we want to    
>>> publish, or indeed say anything at all about, a DL version - also an
>>>    issue for discussion.)
>>>
>>>    [7] 
>>> http://lists.w3.org/Archives/Public/public-swd-wg/2009Mar/0071.html
>>>
>>> -- The HTML representation [1-2] should include labels.
>>>
>>> -- If scripts were used to extract [1-2] from SKOS Reference and to 
>>>    generate the DL version, it might be useful to point to those scripts
>>>    or include them in an appendix.
>>>
>>> -- Instead of replicating this construct separately for the XL 
>>> namespace [8],    maybe SKOS and SKOS-XL could be usefully combined 
>>> into one document
>>>    "Expressions of SKOS Reference in RDF" (since SKOS Reference 
>>> defines both
>>>    the SKOS and XL namespaces).  Such a title would make clear that 
>>> it    derives from SKOS Reference without implying that the document 
>>> is itself
>>>    an RDF schema.
>>>
>>>    [8] 
>>> http://www.w3.org/2006/07/SWD/SKOS/reference/20081001/skos-xl.html
>>>
>>> If the document [1-2] were to do all of the above, might we
>>> not want to formally approve it as a Working Group Note? That
>>> would remove any confusion or ambiguity as to its status.  I hesitate 
>>> because I'm not sure now under what circumstances a reader would 
>>> normally click on or be redirected to this document
>>> and whether, in those contexts, the reader might find it confusing
>>> to encounter something with the status of Note.
>>>
>>> Tom
>>>
>>> -- 
>>> Tom Baker <tbaker@tbaker.de>
>>>
>>
> 
>

Received on Tuesday, 14 April 2009 13:23:09 UTC