- From: Jim Hendler <hendler@cs.rpi.edu>
- Date: Tue, 12 Feb 2008 14:00:55 -0500
- To: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
- Cc: Jeremy Carroll <jjc@hpl.hp.com>, "Web Ontology Language ((OWL)) Working Group WG" <public-owl-wg@w3.org>
I'd be fine with this - but just to be clear, we're talking about documenting OWL 1.1 Full here, not DL which, as I understand it, is not yet under development - apologies if I've missed something from a recent UFDTF decision. -JH On Feb 12, 2008, at 1:09 PM, Ian Horrocks wrote: > > I share Jeremy's desire to maintain a significant degree of rigour > w.r.t. OWL Full; in fact I would say the same for all species/ > fragments/conformance-levels. Moreover, from what Jim says in emails > such as [1] it would seem that he has no objection to this and > perhaps even believes it to be mandatory. Instead, what he seems to > be asking for (in [1] at least) is a more human readable explanation > for those who find model theories difficult to understand. I don't > see any problem with that -- in fact we already have a commitment to > producing such documents and even a UFDTF busily engaged in their > development. So, if we were to agree to produce a "delta to OWL-1.0- > Full" as outlined by Michael in [2] plus suitable documentation for > the MT-challenged, would this satisfy everyone's requirements? > > Ian > > [1] http://lists.w3.org/Archives/Public/public-owl-wg/2008Feb/ > 0069.html > [2] http://lists.w3.org/Archives/Public/public-owl-wg/2008Feb/ > 0068.html > > > On 11 Feb 2008, at 09:05, Jeremy Carroll wrote: > >> >> >> I found Peter's clarification of the semantic options helpful; >> perhaps in allowing me to understand why I was uncomfortable with >> Jim's proposal. >> >> Jim seems to be suggesting something inbetween Peter's "D/ >> Informal" and his "C/ Operational". >> I fear we would find a long term loss in interoperability, for a >> short term gain in ease of reaching a design. >> >> I note that any of Peter's A/ Model theory E/ Transformational or >> F/ Axiomatic can give the same level of rigour and, since we start >> with model theoretic approaches we may as well continue with them, >> if we want this level of rigour. >> >> Jim appears to not want that. >> >> === >> >> I do want to maintain significant degree of rigour with the >> definition of OWL Full for a variety of reasons. >> >> 1) Architectural >> >> My understanding of the Semantic Web is that the semantics is >> attached to the RDF graph, and different layers can *add* >> additional semantics to a graph by means of providing semantic >> extensions (and/or definitions of classes and properties in terms >> of ontology languages such as RDFS and OWL). >> Since these semantics are additions within a strict monotonic >> paradigm, a certain degree of interoperation is provided. >> >> There are a variety of errors in the history of RDF prior to the >> introduction of the RDF Semantics (e.g. containers and >> reification), where an informal and partially operational semantics >> results in systems that do not have such well behaved semantics and >> have unpredictable behaviour. >> >> So the model theoretic semantics provides a discipline against error. >> >> 2) Minimize change >> >> I personally see OWL 1.1 as a small change on OWL 1.0. The two key >> changes I believe are QCRs and subproperty chains. >> >> I am less than happy with almost any change over and above these, >> other than minor corrections. >> >> 3) Product positioning >> >> I don't see HP's OWL Full offering as a "scruff's only" deal (in >> the old AI scruffs v neats debate). >> I see the choice of whether to use OWL (for both Full or DL) in a >> scruffy or neat fashion as an end-user decision. >> The choice of Full or DL is primarily a choice about expressivity >> vs computability guarantees. >> >> In typical OWL Full usage you get to use language features that you >> want, including ones that are not permitted in DL. You use these in >> the fashion that you want (whether neat or scruff). Then maybe an >> off-the-shelf reasoner and reasoner configuration gives you the >> trade-off you want between sufficient entailmenets vs speed - if >> not, you might need to customize your reasoning by selecting say, >> some rules out of a larger set of correct rules that cause a >> computational explosion. >> >> I fear that only having an informal, operational semantics for OWL >> Full would result in OWL Full being narrowed to only certain >> informal and less than precise work. >> >> Jeremy >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> > > "If we knew what we were doing, it wouldn't be called research, would it?." - Albert Einstein Prof James Hendler http://www.cs.rpi.edu/~hendler Tetherless World Constellation Chair Computer Science Dept Rensselaer Polytechnic Institute, Troy NY 12180
Received on Tuesday, 12 February 2008 19:02:24 UTC