RE: Design Issue (4) - constraining 'descriptor'/'prefLabel' card inality for multilingual thesauri

Hey Steve,

Yeah I got really excited when I read the spec about rdf:Alt containers,
because this seemed a way to keep the cardinality of the soks:descriptor
property to one and still have language alternatives.  The RDF specs and the
DC in RDF specs have examples doing things this way.  

So e.g.

<soks:Concept>
	<soks:descriptor>
		<rdf:Alt>
			<rdf:li xml:lang="en">Bangers and mash
(cuisine)</rdf:li>
			<rdf:li xml:lang="fr">Saucisson et pomme de terre
Anglais</rdf:li>
		</rdf:Alt>
	</soks:descriptor>
</soks:Concept>

However Danbri sent me a mail back saying that rdf:Alt is no good because
there is no consistent notion of 'alternative' behind it.  Danbri, is this
really no go?

Al.  

-----Original Message-----
From: Cayzer, Steve [mailto:Steve.Cayzer@hp.com]
Sent: 07 November 2003 14:34
To: 'NJ Rogers, Learning and Research Technology'; Dave Reynolds; Miles,
AJ (Alistair)
Cc: 'public-esw-thes@w3.org'
Subject: RE: Design Issue (4) - constraining 'descriptor'/'prefLabel'
cardinality for multilingual thesauri



First mail to list - hi all! so sorry if I've missed vital context.

1. sound like a workable fallback 
2. works but adds inference load 
3. Urgh! This is similar to the classic subclassing error of OO modelling
(imo) - except it's subproperty of course.

What about saying (apologies for any N3 errors)
<concept> 
   :hasDescriptor [:inLanguage <French>; :value "chaud"];   
   :hasDescriptor [:inLanguage <English>; :value "hot"] .

Or, if you want to keep cardinality constraints, add a level of indirection
<concept> 
   :hasDescriptor [:alternative [:inLanguage <French>; :value "chaud"];
:alternative [:inLanguage <English>; :value "hot"]] .

Steve
> -----Original Message-----
> From: NJ Rogers, Learning and Research Technology 
> [mailto:Nikki.Rogers@bristol.ac.uk] 
> Sent: 07 November 2003 12:14
> To: Dave Reynolds; Miles, AJ (Alistair)
> Cc: 'public-esw-thes@w3.org'
> Subject: Re: Design Issue (4) - constraining 
> 'descriptor'/'prefLabel' cardinality for multilingual thesauri
> 
> 
> 
> Hi Alistair and Dave,
> >
> >> This does have consequences for constraining the data model.  It 
> >> means a node typed as a 'soks:Concept' must then be 
> allowed to have 
> >> multiple 'soks:descriptor' properties, one for each 
> language.  Is it 
> >> then possible in OWL to express the constraint that a concept may 
> >> have one and only one 'soks:descriptor' property for each language?
> >
> > Only if you represent content-in-a-specific-language as a 
> class, which 
> > would mean having a different class and different cardinality 
> > constraint for every language. Which probably wouldn't be workable.
> >
> I've been trying to consider some options here:
> 
> ***********
> 1. throw out the 'descriptor' cardinality constraint for multilingual 
> thesauri (as well as for/as distinct from monolingual 
> thesauri?) and don't 
> worry about it - live with it, & provide recommendation of use
> 
> instead.
> 
> ***********
> 2. model multilingual thesauri in a specific way: express 
> each language's
> 
> interpretation of a concept uniquely by giving the same 
> concept different 
> uri's in each of the languages in question. Then map the 
> concepts (using 
> "owl:equivalentTo").  That way we could still specify exactly 
> 1 preferred 
> label/'descriptor' per concept. Does it upset us to give 
> different uri's to 
> what certain communities believe to be the same concept? I guess how 
> inferencing is then conducted over the thesaurus data (for 
> queries) is then 
> critical & I haven't thought about this in any depth. 
> Therefore I'm not 
> sure if this approach is currently "legal".
> 
> ***********
> 3. Subclass 'soks:Concept' with what we'd understand to be 
> concepts in the 
> context of a particular language. I think this is similar to 
> what Dave is 
> referring to? And yes, it feels cranky:
> 
> e.g.
> 
> 'soks:Concept'
>    |
>    |
> 'soks:English_concept'
> 
> Then we'd potentially have multiple properties (e.g. 
> soks:english_language_concept, soks:japenese_language_concept 
> etc.) hanging 
> off any one 'soks:Concept' in a thesaurus schema.
> [I guess 'soks:english_language_concept' has domain 
> 'soks:Concept' and 
> range 'soks:English_concept' ....]
> Using this approach, we can keep the cardinality constraint = 1 for 
> 'soks:descriptor' properties (because there would be one for each of 
> 'soks:English_concept', 'soks:Japenese_concept', etc)?
> [I suppose 'soks:English_concept' could be further subclassed for 
> American_english etc.]
> However, typically, one then feels that further constraints are now 
> required to protect data integrity. Such as a constraint that the 
> 'descriptor' property value for any [Language]_concept must 
> be in the same 
> language as that [Language]_concept bla bla.
> 
> Hmmm ... :-)
> 
> Nikki
> 
> > But in any case you need to add the qualifier "in any given 
> conceptual 
> > scheme". That definitely makes expressing the cardinality 
> constraint 
> > in OWL unworkable.
> >
> > Dave
> >
> >
> 
> 
> 
> ----------------------
> NJ Rogers, Technical Researcher
> (Semantic Web Applications Developer)
> Institute for Learning and Research Technology (ILRT) 
> Email:nikki.rogers@bristol.ac.uk
> Tel: +44(0)117 9287096 (Direct)
> Tel: +44(0)117 9287193 (Office)
> 

Received on Friday, 7 November 2003 12:20:59 UTC