Options for ordered/labelled collections

Hi Dave, Dan, all,

Can I get some feedback and a sanity check on the options for a collections
proposal for SKOS Core, in light of the recent discussion at the Bristol
SWAD-E meeting ...

The most recent proposal [1] is for two new classes 'skos:Collection' and
'skos:CollectableProperty' and two new properties 'skos:member' and
'skos:memberList', to be used as in:

<skos:Concept rdf:about="c1">
	<skos:prefLabel>Aircraft</skos:prefLabel>
	<skos:narrower>
		<skos:Collection>
			<rdfs:label>aircraft by size</rdfs:label>
			<skos:member rdf:resource="c10"/>
			<skos:member rdf:resource="c11"/>
			<skos:member rdf:resource="c12"/>
			<skos:memberList rdf:parseType="Collection">
				<skos:Concept rdf:about="c11"/>
				<skos:Concept rdf:about="c10"/>
				<skos:Concept rdf:about="c12"/>
			</skos:memberList>
		</skos:Collection>
	</skos:narrower>
</skos:Concept>

Under this proposal, whether or not the members of the collection are
ordered is inferred from the presence of absence of a 'skos:memberList'
property.

The point of 'skos:CollectableProperty' is to support the rule: 

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

... so e.g. 'skos:narrower' would be declared a 'skos:CollectableProperty'.

Discussion
---

The design of this proposal was in part motivated by the current limitations
of RDF query languages and rule languages.  However, Dave R. has suggested
that we should not make design decisions based on current technological
limitations.  Under Dave's suggestion, there is no need for a 'skos:member'
property ... the 'skos:memberList' is sufficient.

So the questions I have are:

(1) Should we remove the 'skos:member' property from this proposal?

(2) If we do remove 'skos:member', how should we express the fact that a
collection is ordered or not?

(3) Is there value in the 'skos:CollectableProperty' suggestion?

(4) Any other comments on name/form of the new terms in this proposal?

Thanks,

Al.



[1] http://lists.w3.org/Archives/Public/public-esw-thes/2004Aug/0082.html

---
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 Tuesday, 5 October 2004 15:18:18 UTC