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Re: maximum cardinality on assertion properties

From: Johannes Koch <johannes.koch@fit.fraunhofer.de>
Date: Tue, 26 Sep 2006 10:01:50 +0200
Message-ID: <4518DE6E.5060106@fit.fraunhofer.de>
To: public-wai-ert@w3.org

Shadi Abou-Zahra wrote:
> Johannes Koch wrote:
>> This reminds me of the RDF container concepts (Bag, Seq, Alt). Does 
>> proposal 2 also allow having one subject property with a bag 
>> referencing several test subjects?
> 
> According to the way the schema is currently formulated, I think this 
> implies changing earl:TestSubject to an rdf:Container (or creating a new 
> earl:TestSubjects class to contain any number of earl:TestSubject 
> individuals).

This I doubt, but I'm not an expert in RDF.

> Not sure what the benefits would be.

AFAIK, using a single property with an rdf:Bag means grouping, whereas 
using multiple properties means ANDing. There seams to be a slight 
difference.

Although asked in the context of earl:subject, this could be a general 
question.

E.g. the UAProf specs 
(<http://www.openmobilealliance.org/tech/profiles/uaprof/ccppschema-20030226>) 
explicitly define some properties to have a Bag or Seq object.

   <rdf:Description rdf:ID='InputCharSet'>
     <rdfs:comment xml:lang='en'>
       Description: List of character sets supported by the device for 
text entry. Property's value is a list of character sets, where each 
item in the list is a character set name, as registered with IANA.
       Examples: "US-ASCII", "ISO-8859-1", "Shift_JIS"
     </rdfs:comment>
     <rdfs:label xml:lang='en'>InputCharSet</rdfs:label>
     <rdf:type rdf:resource='&ns-rdf;Property'/>
     <rdfs:domain rdf:resource='#HardwarePlatform'/>
     <rdfs:range rdf:resource='&prf-dt;Literal'/>
     <rdfs:range rdf:resource='&ns-rdf;Bag'/>
     <prf:ResolutionRule 
rdf:datatype='&prf-dt;ResolutionRule'>Append</prf:ResolutionRule>
   </rdf:Description>
-- 
Johannes Koch - Competence Center BIKA
Fraunhofer Institute for Applied Information Technology (FIT.LIFE)
Schloss Birlinghoven, D-53757 Sankt Augustin, Germany
Phone: +49-2241-142628    Fax: +49-2241-142065
Received on Tuesday, 26 September 2006 08:02:58 GMT

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