- From: Miles, AJ \(Alistair\) <A.J.Miles@rl.ac.uk>
- Date: Tue, 3 May 2005 14:37:23 +0100
- To: "Mark van Assem" <mark@few.vu.nl>
- Cc: <public-esw-thes@w3.org>
> If I understand the new policy statements correctly, this is now a > "proposed change" for the next review, i.e. no changes are > made to the > vocab now. ... ah but we haven't published first Public Working Drafts yet - i.e. technically we haven't completed the first review, we're still in the negotiation phase :) Personally I don't mind when this gets done, before first PWD or in the next interim period. > > Maybe it makes sense to establish some standard phrase to indicate a > proposed change for use on the mailing list. What we were doing during SWAD-E development was to put '[Proposal]' in the subject line of an email sent to public-esw-thes@w3.org ... which seemed to work OK. I'll set up a web page shortly for maintaining a list of proposals that are intended to be reviewed. > > When is the next review scheduled? I propose two months from date of publication of first PWD ... but need to get that approved at the next telecon. Would that be OK with you? Cheers, Al. > > Cheers, > Mark. > > > Miles, AJ (Alistair) wrote: > > Hiya, > > > > I propose to remove all statements involving the > skos:subjectIndicator property *as predicate* from the SKOS > Core Vocabulary itself for now, until we understand this issue better. > > > > Cheers, > > > > Al. > > > > --- > > 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 > > > > > > > > > >>-----Original Message----- > >>From: public-esw-thes-request@w3.org > >>[mailto:public-esw-thes-request@w3.org]On Behalf Of Bernard Vatant > >>Sent: 02 May 2005 12:02 > >>To: public-esw-thes@w3.org > >>Cc: tm-pubsubj > >>Subject: Confused ... RE: Subject Indicators RE: Using SKOS RDF > >>vocabulary in RDFS > >> > >> > >> > >> > >>Oops, in my previous message I have completely confused > >> > >>http://www.w3.org/2004/02/skos/core#Concept > >>http://www.w3.org/2004/02/skos/core/spec/#Concept > >> > >>... it figures > >> > >>1. I should not start by such conceptual things on Monday morning > >>2. I should read more carefully > >>3. I should have followed more closely the recent debates > >>over core and spec > >> > >>Anyway, starting now from those correct premises, all remarks > >>about recursive use of > >>subjectIndicator seem irrelevant at first glance, since URIs > >>are distinct: > >> > >>core:foo skos:subjectIndicator spec:foo > >> > >>But in a topic map environment, it is likely to be > >>interpreted as two URIs identifying the > >>same subject anyway. > >>The subject indicator at > http://www.w3.org/2004/02/skos/core/spec/#foo > >>says to use the URI http://www.w3.org/2004/02/skos/core#foo > >> > >>But if you read closely the Published Subjects > >>recommendation, the URI of a subject > >>indicator is considered as an identifier for the subject it > >>indicates/identifies. > >> > >>So http://www.w3.org/2004/02/skos/core/spec/#foo is an identifier of > >>http://www.w3.org/2004/02/skos/core#foo > >> > >>IOW, the following topics should be merged by a topic map > application > >> > >><topic id="foo-core"> > >> <subjectIdentity> > >> <subjectIndicatorRef > >> xlink:href="http://www.w3.org/2004/02/skos/core#foo"/> > >> </subjectIdentity> > >></topic> > >> > >><topic id="foo-spec"> > >> <subjectIdentity> > >> <subjectIndicatorRef > >> > >>xlink:href="http://www.w3.org/2004/02/skos/core/spec/#foo"/> > >> </subjectIdentity> > >></topic> > >> > >>So the real issue is : why do we need different URIs, since > >>http://www.w3.org/2004/02/skos/core#foo could directly point > >>to the subject indicator ... > >> > >>Bernard > >> > >> > >>>-----Message d'origine----- > >>>De : public-esw-thes-request@w3.org > >>>[mailto:public-esw-thes-request@w3.org]De la part de Bernard Vatant > >>>Envoyé : lundi 2 mai 2005 11:03 > >>>À : public-esw-thes@w3.org > >>>Cc : tm-pubsubj > >>>Objet : Subject Indicators RE: Using SKOS RDF vocabulary in RDFS > >>> > >>> > >>> > >>> > >>>Hello Dean, and all > >>> > >>> > >>>>We have been looking into using the SKOS RDF vocabulary > >>>>(http://www.w3.org/2004/02/skos/core.rdf) with > >> > >>RDFS-enabled tools, and > >> > >>>>have found some anomalies that make it difficult to > >> > >>understand how SKOS > >> > >>>>is intended to be used. In particular, we have loaded > >> > >>the vocabulary > >> > >>>>into SWOOP, Protege and RDF Gateway. When we first did > >> > >>this, we thought > >> > >>>>we must have found bugs in these tools, because of the > >> > >>strange results > >> > >>>>that we got. But when we looked into core.rdf, it seems > >> > >>that these > >> > >>>>things are part of SKOS itself. > >>> > >>>Sure they are. I had not looked at SKOS in SWOOP before, I > >> > >>just did, and indeed some > >> > >>>things look weird. > >>> > >>> > >>>> <rdfs:Class rdf:ID="Concept"> > >>>> <rdfs:label xml:lang="en">Concept</rdfs:label> > >>>> ... > >>>> <skos:subjectIndicator > >>>>rdf:resource="http://www.w3.org/2004/02/skos/core/spec/#Concept"/> > >>>>... > >>>> </rdfs:Class> > >>> > >>>This recursive use of subjectIndicator is certainly not a > >> > >>good idea, neither for this > >> > >>>element, nor other ones in the whole specification. The > >> > >>information carried is that the > >> > >>>URI http://www.w3.org/2004/02/skos/core/spec/#Concept > >> > >>provides a definition of the > >> > >>>resource it defines. At best, it is tautological. Seems to > >> > >>me that the property > >> > >>>skos:subjectIndicator should not use as declared value the > >> > >>URI of its subject, > >> > >>>that is any > >>>declaration. > >>> > >>> a:foo skos:subjectIndicator a:foo > >>> > >>>should be avoided > >>> > >>>Reminder : the intended use of subjectIndicator is > >> > >>providing documentation of > >> > >>>vocabularies, such as > >>> > >>> a:foo skos:subjectIndicator b:bar > >>> > >>>Where b:bar can be dereferenced to provide a human-readable > >> > >>resource indicating the > >> > >>>subject, according to > >>> > >> > >>http://www.oasis-open.org/committees/download.php/3050/pubsubj > >>-pt1-1.02-cs.pdf > >> > >>>(which BTW is the official OASIS Published Subjects > >> > >>recommendation, and should > >> > >>>replace the > >>>reference to the older draft > >>> > >> > >>http://www.oasis-open.org/committees/tm-pubsubj/docs/recommend > >>ations/general.htm in the > >> > >>>SKOS document) > >>> > >>>"A subject indicator is an information resource which > >> > >>provides some kind of > >> > >>>compelling and > >>>unambiguous indication of the identity of a subject to > >> > >>humans. It may be a textual > >> > >>>definition, description or name; it may be a visual, audio or other > >>>representation of the > >>>subject; or it may be some combination of these. A subject > >> > >>indicator is > >> > >>>distinct from the > >>>subject that it indicates." > >>> > >>>Certainly http://www.w3.org/2004/02/skos/core/spec/#Concept > >> > >>is conformant to the above > >> > >>>definition *if used from an external vocabulary*. > >>> > >>> myDomain:Concept skos:subjectIndicator skos:Concept > >>> > >>>Topic map reading of the latter being that myDomain:Concept > >> > >>and skos:Concept, > >> > >>>or at least > >>>their URIs define/identify the same subject, so the > >> > >>difference with the > >> > >>>following is very > >>>subtle: > >>> > >>> myDomain:Concept owl:equivalentClass skos:Concept > >>> > >>>or even worse: > >>> > >>> myDomain:Concept owl:sameAs skos:Concept > >>> > >>>since in topic map land, everything is a topic (read in OWL > >> > >>: everything is an > >> > >>>individual) > >>> > >>>But clearly, the recursive declaration > >>> > >>> skos:Concept skos:subjectIndicator skos:Concept > >>> > >>>seems to be inconsistent with : "A subject indicator is > >> > >>distinct from the > >> > >>>subject that it > >>>indicates". > >>> > >>>Moreover, in this triple, skos:Concept is implicitly > >> > >>understood when subject of > >> > >>>the triple > >>>as an abstract resource (Concept as owl:Class), and when > >> > >>object of the triple, as the > >> > >>>information resource describing this abstract resource for > >> > >>humans (the table in the spec > >> > >>>document). Web identity crisis strikes again. > >>>See http://www.ontopia.net/topicmaps/materials/identitycrisis.html > >>> > >>> > >>>Adding to the logical mess is certainly the following > >>> > >>>skos:subjectIndicator rdfs:range foaf:Document > >>> > >>>... since it entails, along with > >>> > >>>skos:Concept skos:subjectIndicator skos:Concept > >>> > >>>the following triple > >>> > >>>skos:Concept rdf:type foaf:Document > >>> > >>>... which is indeed very bizarre > >>> > >>>Now the real issue is "who cares?". Seems unlikely that any > >> > >>(useful) inference will ever > >> > >>>be done on the core vocabulary itself, except for the above > >> > >>academic exercise. Inference > >> > >>>will be done inside and across vocabularies, for query of > >> > >>relevant indexed resources, > >> > >>>vocabulary mapping, semantic extension/restriction of > >> > >>search etc ... At that level, will > >> > >>>the above logical oddities be really a problem? > >>> > >>>Cheers > >>> > >>>Bernard > >>> > >>> > >> > >>************************************************************** > >>******************** > >> > >>>Bernard Vatant > >>>Senior Consultant > >>>Knowledge Engineering > >>>bernard.vatant@mondeca.com > >>> > >>>"Making Sense of Content" : http://www.mondeca.com > >>>"Everything is a Subject" : http://universimmedia.blogspot.com > >>> > >>> > >> > >>************************************************************** > >>******************** > >> > >>> > >>> > >> > >> > >> > > > > -- > Mark F.J. van Assem - Vrije Universiteit Amsterdam > mark@cs.vu.nl - http://www.cs.vu.nl/~mark > >
Received on Tuesday, 3 May 2005 13:37:40 UTC