[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: Web service and Semantic Web
Hi, > The distinction, then, between 'Web Service' and 'Semantic Web' is whether the > nodes of that web can be trusted, by the promulgators of the larger scheme , to > implement unique (and perhaps uniquely useful) functionality. Perry, thank you very much for your comment. In the Web Service, input and output schema is fixed and can be trusted with digital signatures, but the result of services (quality of services) might not be tr usted. Another question is how can we trust the assertions in the global environmen t, the Web. Suppose I want to publish some assertions with digital signature. My digital certificate is signed by a commercial CA such as VeriSign, but the cert was very easy to get. In this case, can anyone who doesn't know me or my orgnizatoin trust my assertions? We can limit acceptable classes of the certificates or root CAs, but it migh t compromise the advantage of the Semantic Web (network effect). Best regards, Naohiko At 11:04 2000/12/29 -0500, W. E. Perry wrote: > Whether or not I can answer N. Uramoto's question to his satisfaction, I a m very > grateful for this succinct statement of it. IMHO, he has pinpointed precis ely > where Semantic Web enthusiasm runs off the rails: the question of how, an d based > on what, the requisite inference is performed. In the past several days on this > list we have seen at least three threads raise similar questions of pre-or dained > semantics. Whether the question arises with regard to namespaces, or to sc hemas, > or to messaging specifications, the underlying problem is the same. > > As Semantic Web advocates continue to elaborate their vision, it is increa singly > clear that they imagine a lattice of interlocking references, definitions and > assertions. Within such a scheme, resolving, or instantiating, or otherwise > realizing the particular manifestation of any particular node or component of > this lattice on any particular occasion necessarily involves inferences, > principally as to how to preserve and express the semantics of referenced > resources within this new realization. Because this Semantic Web rests on a > fundamental premise of building new assertions upon reference to previous ones, > it relies not only upon the fixity of those assertions but also upon a mec hanism > which can be counted on to constrain any new expression to the scope, or m ore > precisely the intersecting scope, of the underlying referenced assertions on > which it is predicated. Autonomous nodes, implementing idiosyncratic metho ds, > cannot be counted on to respect that limitation. > > The distinction, then, between 'Web Service' and 'Semantic Web' is whether the > nodes of that web can be trusted, by the promulgators of the larger scheme , to > implement unique (and perhaps uniquely useful) functionality. Stated anoth er way, > the difference is whether the outcome or rendition from a node is governed > principally by its own functionality or principally by the received semant ics on > which it operates. That distinction is so basic that it is not surprising that > Uramoto-san wonders 'What is the relationship between them? Are they compl etely > different things? or similar but supported by different communities?' The answer, > I fear is that proponents of both camps do inhabit this list, where far to o often > they are simply talking past each other. The gulf may, in fact, be unbridg eable, > but now at least we have the specific differences laid out for any who might > relish the debate. > > Respectfully, > > Walter Perry > > > URAMOTO Naohiko wrote: > > > Web Service: > > The Web is a set of software components (methods) > > No inference > > Ontology > > We can find services from open directories such as UDDI > > Digital signature is used for integrity and non-repudiation > > > > Semantic Web: > > The Web is a set of assertions > > Inference > > Ontology > > (How we can find assertions?) > > Digital signature is used for qualifying assertions (I think it is not c orrect > > use of digital signature...) > Naohiko URAMOTO ($B1:K\(B $BD>I'(B) uramoto@j... Internet & Language Technology, Tokyo Research Laboratory, IBM Research
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