[Proposal][SKOS-Core] Revised proposal for ordered/labelled colle ctions

Hi,

Based on recent discussions and feedback, here is a revised proposal for
additions to SKOS Core for representing ordered/labelled collections of
concepts:

Add the following classes:

	- Collection
	- OrderedCollection (sub-class of Collection)
	- CollectableProperty

Add the following properties:

	- member (domain: Collection, range: rdf:Resource)
	- memberList (domain: Collection, range: rdf:List)

To illustrate the intended usage by example, an *unordered* labelled
collection would be represented in RDF/XML as:

<rdf:RDF 
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 
  xmlns:skos="http://www.w3.org/2004/02/skos/core#">

  <skos:Concept rdf:about="http://my.example.org/concept#102">
    <skos:prefLabel>Aircraft</skos:prefLabel>
    <skos:narrower>
      <skos:Collection>
        <rdfs:label>Aircraft by function</rdfs:label>
        <skos:member rdf:resource="http://my.example.org/concept#1024"/>
        <skos:member rdf:resource="http://my.example.org/concept#1026"/>
        <skos:member rdf:resource="http://my.example.org/concept#1027"/>
        <skos:member rdf:resource="http://my.example.org/concept#1028"/>
        <skos:member rdf:resource="http://my.example.org/concept#1029"/>
      </skos:Collection>
    </skos:narrower>
  </skos:Concept>

</rdf:RDF>

An *ordered*, labelled collection would be represented in RDF/XML as:

<rdf:RDF 
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 
  xmlns:skos="http://www.w3.org/2004/02/skos/core#">

  <skos:Concept rdf:about="http://my.example.org/concept#56">
    <skos:prefLabel>Countries</skos:prefLabel>
    <skos:narrower>
      <skos:OrderedCollection>
        <rdfs:label>Countries by size</rdfs:label>
        <skos:memberList rdf:parseType="Collection">
          <skos:Concept rdf:about="http://my.example.org/concept#564"/>
          <skos:Concept rdf:about="http://my.example.org/concept#565"/>
          <skos:Concept rdf:about="http://my.example.org/concept#566"/>
          <skos:Concept rdf:about="http://my.example.org/concept#568"/>
          <skos:Concept rdf:about="http://my.example.org/concept#560"/>
          <skos:Concept rdf:about="http://my.example.org/concept#562"/>
        </skos:memberList>
      </skos:OrderedCollection>
    </skos:narrower>
  </skos:Concept>

</rdf:RDF>

The following points are also part of this proposal:

(1) Collections may be nested as members of other collections.

(2) Wrt 'CollectableProperty' the following rule applies:

	(?p rdf:type skos:CollectableProperty)
	(?x ?p ?c)
	(?c skos:member ?m)
	->
	(?x ?p ?m)

(3) skos:narrower is declared to be of type skos:CollectableProperty

(4) Wrt 'memberList' the following dependency rule applies:

	(?c skos:memberList ?l)
	elementOfList(?e,?l)
	->
	(?c skos:member ?e)

That's all.

------ 

---
Alistair Miles
Research Associate
CCLRC - Rutherford Appleton Laboratory
Building R1 Room 1.60
Fermi Avenue
Chilton
Didcot
Oxfordshire OX11 0QX
United Kingdom
Email:        a.j.miles@rl.ac.uk
Tel: +44 (0)1235 445440

Received on Monday, 11 October 2004 16:16:18 UTC