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 07:13:39 UTC