- From: Shi, Xuan <xshi@GEO.WVU.edu>
- Date: Fri, 17 Mar 2006 19:21:25 -0500
- To: "'Josh@oklieb '" <josh@oklieb.net>, "'public-sws-ig@w3.org '" <public-sws-ig@w3.org>
- Cc: "'drew.mcdermott@yale.edu '" <drew.mcdermott@yale.edu>
We are outsiders anyway as Dr. McDermott said. We who get involved with OGC services have to also consider how our users to understand the meaning of the services, how to use the services after we developed them, and we generated lots of standards for the community to share the meaning of the services. That means, if we follow the standards, we can consume the services without question. The insiders of this community, however, concerns more about machine other than human. They focus on the logic relationship among the varied components in their systems, other than the meaning or semantics of the services. That's why my European friend told me there is no other semantics in the eyes of such people except logics. Unfortunately I am more concerned about something besides logics inside the services. That's why I am an outsider for this community. If you have no such interest focusing on the machines, you are an outsider too. However, I have to remind such people to consider why we need anti-monopoly laws in this country and the world. Those giant companies that have monopoly control in the domain have to adjust their behavior to cope with such law. Since once someone has the vested interests through monopoly control in one domain, it is easy for such person or company to cheat the public community to raise the price for its product or service unreasonably. That's the same analogy to SWS community. If anyone who can do something by an easy and simple way, but this person just tell the customers that he or she has to use a complex system to do the same thing, how can you judge such behavior? By simple approach, it may cost $50k while by complex approach, it may cost more than $500K. Besides research and debate, we also need public hearing to tell the general community how can they do something in an easy, simple and understandable way without those more and more complex frameworks and systems. In this case, there is no way to charge $500k for a $50k cloth. Xuan -----Original Message----- From: Josh@oklieb To: public-sws-ig@w3.org Cc: drew.mcdermott@yale.edu Sent: 3/17/06 12:28 PM Subject: Re: Semantics of WSDL vs. semantics of service This discussion is also giving me an inclination towards preemptive deletion of sws-id emails, which is unfortunate. Between the confusion of terms (as pointed out, using composition for binding) and "descent" to XML Schema arguments, it can't be said to advance the cause. It is rather amazing (heartening or disheartening, I'm not sure) to see arguments rehashed which have been going on in the OGC (Open Geospatial Consortium) for years. For example, the use of private XML message schemas versus SOAP formulations, whether URLencoded service invocations using HTTP GET are still important, equating SOAP/WSDL with RPC and in turn with the full spectrum of Web service possibilities, the idea that the useful information abstractions of WSDL should command slavish devotion to its syntax (as well as claim to completeness). In truth, and disjoint vocabulary aside, we are all fairly well agreed on the general information which is needed to productively discover, bind, and consume a remote service over the Web. We should focus on the substantive general questions that remain. For instance, is it advisable to abstract away all knowledge that an operation is being invoked on a remote service over the Web (probably not)? Should services be self-describing (probably so)? Is coupled content an important part of service semantics (yes and yes)? Does WSDL impart all the information needed (for a machine) to use a remote service outside of a small circle of friends (no). Is it important to represent in service information how a service processes inputs to generate outputs (yes, different geocoding services for example have their own idiosyncratic heuristics irrespective of the syntax)? Where are syntax standards useful for interoperability? Should we get all wound up about whether this additional service information is contained in a WSDL <definitions> element, referenced from within a WSDL <definitions>, outside of a WSDL <definitions> (not really that important a question)? Cheers, Josh Joshua Lieberman, Ph.D. Principal, Traverse Technologies Inc. mailto:jlieberman@traversetechnologies.com tel +1 (617) 395-7766 fax +1 (775) 514-6621 On Mar 16, 2006, at 11:20 PM, Drew McDermott wrote: [Shi, Xuan] ... I know I said something different from the others. Such as what is service composition? My definition is different from the so-called "standard" meaning, but I think it is more realistic and understandable for all users who are not programmers and AI professionals to consume Web services. This admission is simply astonishing. I pointed this discrepancy out to Xuan months ago in private correspondence. The SW community disagrees about many aspects of the "service composition problem," but everyone agrees it involves computers doing some sort of combination of solutions of small web-service problems in order to solve bigger problems. Because the English word "compose" is ambiguous, and because Xuan came into this area as an outsider, he originally thought it meant human composition of web-service requests (as one would compose an SQL request, for instance). An honest misunderstanding. But it is not an acceptable response to such a revelation to continue to use the semi-standard term in one's nonstandard way. To do so is to guarantee that any discussion using the term will be meaningless, chaotic, and ultimately acrimonious. (The more so if there are _other_ terms that are being used in nonstandard ways; who knows?) I don't see why anyone would pursue this any further. -- -- Drew McDermott Yale University Computer Science Department
Received on Saturday, 18 March 2006 00:21:44 UTC