Re: Design Issue (4) - constraining 'descriptor'/'prefLabel' cardinality for multilingual thesauri

Cayzer, Steve wrote:

> 1. sound like a workable fallback 

Agreed.

> 2. works but adds inference load 

Would need a lot of owl:differentFrom assertions in order to actually have 
the cardinality constraints bite but that would be the case anyway.

> 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"] .

That was sort of what I was suggesting earlier, except that I'd use 
xml:lang to convey the language and was suggesting a descriptorSchema 
property for descriptors.

The to me this is better modelling but you can't express the relevant 
cardinality constraints in OWL.

> 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"]] .

That doesn't help with the cardinality. What Alistair wanted was a 
cardinality constraint that means there is only one perferredTerm in each 
language (in each descriptiveSchema). It is the "in each" subclauses that 
is hard to express in OWL without introducing an artificial looking class 
hiearchy.

Dave


>>-----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)
>>


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Received on Friday, 7 November 2003 10:24:18 UTC