- From: Guus Schreiber <schreiber@cs.vu.nl>
- Date: Wed, 29 Nov 2006 12:57:41 +0100
- To: SWD WG <public-swd-wg@w3.org>
- CC: Sean Bechhofer <sean.bechhofer@manchester.ac.uk>, Antoine Isaac <aisaac@few.vu.nl>
All, It seems to be time to start an Issues List. This rule issue should become part of it. I see various solutions, but it's not yet clear to which one we should prefer. An issues list helps the tracking process and also records the rationale for the decision taken to resolve the issue. As an example of an Issues List see the OWL Issues List [1]. Appendix 7 of this document describes the issue process: [[ Issues have the following life cycle: - Issues are submitted by members of the working group. Such issues are marked *raised*. The process for submission is described in Appendix 6 above - The chair may *open* an issue, normally assigning an owner. - The issue list is reviewed periodically. Normally, discussion is only in order for open issues. At times the chair may deem that a review is in order to attempt to resolve, merge, close, postpone and otherwise clean up the list. - Issues are *closed* by decision of the WG. The chair determines when the WG is ready to decide, usually in response to a proposal from the issue owner. The resolution is recorded in the issues list. ]] I suggest we adopt the same issue process. We can maintain the Issues List in the wiki. Guus [1] http://www.w3.org/2001/sw/WebOnt/webont-issues.html Sean Bechhofer wrote: > > > On 27 Nov 2006, at 23:04, Antoine Isaac wrote: > >> >> Hi Sean, >> >> You pointed at a very important problem here >> >>> >>> >>> The SKOS Core Guide includes reference to rules: >>> >>> http://www.w3.org/TR/swbp-skos-core-guide/#secaboutrules >>> >>> [[ >>> Inference rules are part of SKOS Core. Inference rules are >>> described in prose, and where appropriate are expressed using the Jena >>> 2 rule syntax [Jena Inference], or as RDF statements using the OWL >>> vocabulary [OWL]. Inference rules appear in boxes such as: >>> >>> An example rule. >>> >>> (?x ex:p ?y) >>> -> >>> (?x ex:q ?y) >>> >>> prefix ex: <http://www.example.com/eg#> >>> >>> ]] >>> >>> I can see what's going on here, but it makes me a little >>> uncomfortable. If the SKOS recommendation is to make use of additional >>> infrastructure, shouldn't this be couched in terms of a standards >>> (e.g. RIF when it appears) rather than referring to some particular >>> implementation (Jena rules)? >> >> I completely agree with you. But I think that at the time when these >> rules where specified standards where not easily available, nor really >> helpful to get a simple message get through (RuleML/SWRL?) >> >>> >>> Is there going to be some notion of comformance? For example, does >>> this mean that I *cannot* provide a SKOS implementation without having >>> some RDF repository that implements the rules -- and in that vein, >>> what are the precise intended semantics of these rules? >> >> Alistair would perhaps be better placed than me to answer. However, I >> have worked with SKOS for quite a while now, and to me it is now quite >> natural to consider that the rules are part of the spec, and therefore >> should be implemented if one wants to implement a proper SKOS engine. >> This explain perhaps there have been cases of vocabularies represented >> using SKOS, but no "official" SKOS inference engine... (though such a >> thing wouldn't be too hard to implement, I suppose) >> Concerning the semantics of the rules, well I suppose that the idea >> was just to have some production rule that would enable to specify >> formal inferences fitting what the SKOS model was trying to render. > > I'm not a hardline DLista, but with my vaguely formal hat on, I'd > certainly want to see this clarified. That would then make it easier to > see if such an engine really wasn't "too hard to implement...." > >> And I supposed that if OWL had offered means to represent general >> relational composition, there wouldn't have been such Jena-like >> axioms, but just OWL ones, as for e.g. the transitivity of skos:broader. > > I think the property chain inclusion axioms in the proposed OWL 1.1 [1] > would cover the subject generality rule. Not sure about the others though. > >> Whatever be the case, it is clear that this should be clarified for >> further version of SKOS. Notice by the way that some of the concerned >> axioms (either OWL ones or "rules") are quite controversial (well, I >> disagree with the relevance of some, and am not the only one), and >> might disappear from a further version of SKOS. > > Ok. > > Sean > > [1] http://owl1_1.cs.manchester.ac.uk/overview.html > > -- > Sean Bechhofer > School of Computer Science > University of Manchester > sean.bechhofer@manchester.ac.uk > http://www.cs.manchester.ac.uk/people/bechhofer > > > > -- Vrije Universiteit Amsterdam, Computer Science De Boelelaan 1081a, 1081 HV Amsterdam, The Netherlands T: +31 20 598 7739/7718; F: +31 84 712 1446 Home page: http://www.cs.vu.nl/~guus/
Received on Wednesday, 29 November 2006 11:58:19 UTC