- From: <Alois.Reitbauer@profactor.at>
- Date: Thu, 1 Sep 2005 16:22:35 +0200
- To: public-sws-ig@w3.org
Hello Shi, In fact you have given a good example whiy more semantics in web services is needed with your example. That "reverse engineering" approaches will not work out is quite clear. Once you have removed explicit semantics it is very difficult to imposible to reconstruct it. I also agree that reconstructing frame-based or object-oriented data structures into OWL does not help to express semantics. Anyway the help you in creating a semantic model for your application - as a first step. This model anyway has to be extended by a human user. explaining in more detail what this service does. Just from the WSDL it cannot be extracted that the location information is the location of the given address. This is also implicit information. A semantic information model can help to express this meaning. Reverse engineering anyway is only one side of the medal. The more interesting question is how do we design, model, and implement the more complex system we will build in the future. Today we use UML to create an object-oriented conceptual model of our application. We use an ERP diagram to model our data structures. Lateron we implement the system in an object oriented language like C#, Java whatever. The initial conceptual model we developed in UML however is only implicit later-on in the code. Although we have a sound data model we later-on struggle with mapping of relational data to object oriented representations. The question now is how to we want to develop tomorrow and how semantic technologies can help us there.Can we build more self-explainatory application with more explicit semantics? ____________________________________________ Alois Reitbauer Multi Agent Systems Profactor Produktionsforschungs GmbH Im Stadtgut A2 A-4407 Steyr/Gleink Austria Tel. +43 (7252) 885-170 Fax: +43 (7252) 885-101 E-Mail: Alois.Reitbauer@profactor.at Web: www.profactor.at ____________________________________________ VERANSTALTUNGEN/ EVENTS SMART Automation | 5. - 7. Oktober 2005, Design Center Linz | Fachmesse für industrielle Automation | Besuchen Sie uns auf Stand Nr. 203! | Wir freuen uns auf Ihr Kommen! SimForumSteyr'05 - Produktions- und Logistikkonzepte am optimalen Betriebspunkt | Mit Simulation & Optimierung Zielkonflikte lösen, Störungen beherrschen, Potentiale nutzen | Fachtagung | 13. Oktober 2005 | www.profactor.at/SimForumSteyr05 "Shi, Xuan" <xshi@GEO.WVU.edu> Sent by: public-sws-ig-request@w3.org 01.09.05 14:55 To "'Carine Bournez '" <carine@w3.org>, "'Battle, Steven Andrew '" <steve.battle@hp.com> cc "'public-sws-ig@w3.org '" <public-sws-ig@w3.org> Subject RE: FWD [Work in Progress on Semantics for Web Services (Advance Notice)] Dear Dr. Bournez: I joined this working group and mailing list but cannot add my comments into the archive. Maybe my opinion is not welcome but I hope more and more people can understand what' wrong for those research approaches on semantic Web services research when they are used in real world development. I think I contacted you and many other W3C staffs, directors and writers of OWL-S, WSMO, WSDL-S. I hope people in this working group will not keep silence on those known problems. In my opinion, the mechanism of OWL-S looks like a backward-engineering process. Since WSDL is the outcome of OOP, then what OWL-S can do is only restore the object hierarchy and relationship in the development process of OOP. In this way, every object used in the Web services can be associated with others under such framework but OWL-S cannot describe the meaning of the objects used in the OOP. WSDL-S makes things worse since it only “adds” semantics onto certain objects while remains the others undefined, that is to say, given the example of Address Finder Web Service (URL can be accessed at: http://arcweb.esri.com/services/v2/AddressFinder.wsdl ), WSDL-S would only add semantics onto such WSDL elements like street, intersection, city, state_prov, zone, country, user name, password, but ignore the other elements such LocationInfo, ArrayOfLocation, Location[], description1, description2, addressFinderOptions, token, matchType, etc. just because they are not meaningful. Thus the whole WSDL file will be a mess for requesters to understand and use. WSMO creates a conceptual model to describe the meaning of the service and probably can be a useful approach to develop semantic Web services. Unfortunately, WSMO by now has to “ground” to WSDL to connect both systems together and to derive the service semantics. If WSDL is NOT the appropriate source from which to derive data and service semantics, WSMO just associates with a wrong object and thus cannot get the correct result. Thus if there is no way to “ground” to WSDL, WSMO is useless as a stand-alone framework. In conclusion, the source of the problem in their research on semantic Web services is that researchers just used some simple business transaction models and then the whole process is simplified. That is to say, all WSDL elements used in such simple models are intuitive and self-understandable. However, given the example in Address Finder Web Service, most of WSDL elements are meaningless, redundant, and irrelevant to the users to set up a direct relation between the input variables and output results. When we try to use such real-life cases to test those mechanisms, then we can find the true problems. I tried to CMU's WSDL2OWLS tool to convert the WSDL file of Address Finder Web Service into OWL-S, the result is almost meaningless and users still cannot understand the meaning of the service. Unfortunately, CMU's Web site for testing their tool is down and maybe they just knew OWL-S approach cannot solve the problem. What's the semantics for Address Finder Web Service? The direct and explicit meaning of this Web service is: if the user can provide user name, password, and address information on street, city, state (or province), zip/post code, then the service will return the location of the input address. I suggest that researchers should give up dealing with those simple business transaction models. I know SWS now is a big "business" but please test your approaches and see if your approach can describe the meaning of "Address Finder Web Service". If it fails, you have to consider what's wrong and reformat your approach. Don't tell people that your approach can work find with credit card transaction, buy book, ticket, purchase order, etc. etc.... They are just meaningless in the real world. Any comments and suggestions will be greatly appreciated. I hope W3C and SWS committee members will not keep silence any more to this challenge since many of them already knew the content of this message for a rather long time. I look forward to hearing from you. Best wishes, Xuan -----Original Message----- From: Carine Bournez To: Battle, Steven Andrew Cc: public-sws-ig@w3.org Sent: 9/1/05 6:11 AM Subject: Re: FWD [Work in Progress on Semantics for Web Services (Advance Notice)] On Thu, Sep 01, 2005 at 10:50:47AM +0100, Battle, Steven Andrew wrote: > > Carine, > Can you shed any light on the decision here to establish a charter for a > new working group rather than - or perhaps in addition to - a lighter > weight incubator activity. The attendee poll at the FSWS workshop found > little enthusiasm for such a working group. What caused this shift in > opinion at the W3C? > Steve. Steve, all, This "Advance Notice" is precisely aiming at gathering feedback about the way to go. W3C Members are aware of lightweight process and should react on member-ws@w3.org about this process. Thank you for raising this point.
Received on Thursday, 1 September 2005 14:22:50 UTC