W3C home > Mailing lists > Public > public-esw-thes@w3.org > October 2008

Re: [SKOS] About notations and datatypes (was Re: Comments on Vocabularies document, v 1.15)

From: Norman Gray <norman@astro.gla.ac.uk>
Date: Wed, 8 Oct 2008 12:17:13 +0100
To: Antoine Isaac <aisaac@few.vu.nl>
Message-Id: <052D0AE5-61EE-4A66-99AE-AA71FEED1132@astro.gla.ac.uk>
Cc: SWD WG <public-swd-wg@w3.org>, SKOS <public-esw-thes@w3.org>, Alasdair Gray <agray@dcs.gla.ac.uk>


Antoine, hello.

On 2008 Oct 4, at 14:26, Antoine Isaac wrote:

>> Now, I'm not a real expert in RDF datatypes, it would be great if  
>> someone on the list could validate your approach with more  
>> certainty. Especially, if it is something that shall be encouraged  
>> or discouraged (my two cents is that it should be encouraged if we  
>> want people to use skos:notation). Jeremy's opinion would be  
>> useful, as he co-authored [3]!

Thanks -- Jeremy's opinion would indeed be valuable here.



A slightly broader point:  We were hoping to get the Vocabularies  
document to an IVOA Recommendation within the next month or so, thus  
before the SKOS document itself was due to become a W3C REC.  We  
justified this questionable practice to ourselves because we were  
using only core features of SKOS, unlikely to change between the  
current drafts and the REC.  However I see from the list of issues  
which have appeared on the SWD list, that things like skos:notation  
are still to some extent contestable [1].  This is making me worry  
that perhaps we should hold back after all.

Do you think that there is likely to be significant change to the sort  
of core SKOS aspects we've refererred to in our document?  Or, a  
related question, is end-December 2008 still the expected date for  
SKOS to become a REC?  (If so, it's close enough that the argument for  
going ahead out of sync starts to evaporate).

Best wishes,

Norman


[1] http://www.w3.org/2006/07/SWD/track/issues/184





On 2008 Oct 4, at 14:26, Antoine Isaac wrote:

>
> Hello Norman,
>
> Glad that my comments on IVOA vocabularies document could help a bit!
>
> About the following issue:
>
>>
>>> - I think your proposed example for notations is not compliant  
>>> with what the SKOS Reference and Primer say about these [1,2].  
>>> skos:notation should be used with literals with a specific  
>>> datatype, as in
>>> ex:udc512 skos:prefLabel "Algebra" ;
>>> skos:notation "512"^^ex:myUDCNotationDatatype .
>>> (and yes, it is not a very simple representation. Which is why we  
>>> left the "private use tags with skos:prefLabel" option available...)
>>
>> Ah, we hadn't spotted that.  Given that a vocabulary and its  
>> notations are defined in a PDF document http://foo/bar.pdf (which  
>> is distinct from the current document), I suppose I can refer to  
>> this as follows:
>>
>> <#concept>
>>  skos:notation "1.2.3"^^<#notation> .
>> <#notation>
>>  dc:description "The notation is defined in the document http://foo/bar.pdf 
>> " .
>>
>> Would that be correct?  It appears to be consistent with the text  
>> in SKOS Reference section 6.5.
>>
>> In this context, I can see little benefit in creating an XSchema  
>> datatype, and requiring something like that would increase the  
>> complication of the Recommendation we're writing.
>
> I would be rather sceptical about defining an explicit XML datatype,  
> too.
> Honnestly I've always been sceptical about the skos:notation stuff,  
> because it seemed to be forcing people to make too complex things.
> But in fact if your suggestion is correct (and it seems to be!) that  
> would give a good balance, anchoring a string to a well-identified  
> and accessible notation-defining space and still not defining this  
> space formally. I'd be tempted to mention more explicitly this  
> practice in the Primer, also (in which case it would be our turn to  
> be thankful to you ;-)
>
> Now, I'm not a real expert in RDF datatypes, it would be great if  
> someone on the list could validate your approach with more  
> certainty. Especially, if it is something that shall be encouraged  
> or discouraged (my two cents is that it should be encouraged if we  
> want people to use skos:notation). Jeremy's opinion would be useful,  
> as he co-authored [3]!
>
> Cheers,
>
> Antoine
>
> [3] http://www.w3.org/TR/2006/NOTE-swbp-xsch-datatypes-20060314
>
>
>
>>
>> Thanks again for the comments.  Best wishes,
>>
>> Norman
>>
>>
>
>
>

-- 
Norman Gray  :  http://nxg.me.uk
Dept Physics and Astronomy, University of Leicester
Received on Wednesday, 8 October 2008 11:17:52 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:39:00 GMT