- From: Shi, Xuan <xshi@GEO.WVU.edu>
- Date: Wed, 7 Sep 2005 22:50:38 -0400
- To: "'Amit Sheth @ LSDIS '" <amit@cs.uga.edu>, "'public-sws-ig@w3.org '" <public-sws-ig@w3.org>
- Cc: "Shi, Xuan" <xshi@GEO.WVU.edu>, "'Juggy.Jagannathan@mail.wvu.edu '" <Juggy.Jagannathan@mail.wvu.edu>
Dear Dr. Sheth: Sorry to make you unhappy but I just want to generate more discussion and attention on such issues and problems in developing semantic Web services other than keep silence to the known problems, such as how can WSDL-S add semantics onto selected elements in the WSDL file for Address Finder Web Services while may leave the others undefined, or how OWL-S/WSMO can solve such problems. Also I don't think it's a problem for such typical case as somebody said this WSDL file does not comply with WSDL 2.0. It's a design issue and the same service can be implemented in WSDL 2.0 and then the problem is still there. Moreover, I remembered that Dr. Goodwin told me that document-based input variables can be defined semantically by WSDL-S (maybe I misunderstood him) but I just don't know how he did that. Given the following example, those 11 Web services that can be found at: http://157.182.136.76/AItest/ws/AIDemo1/WebForm1.aspx have exactly the same content of WSDL except the location of the services. Of course those 11 Web services will perform different functions, but how can you describe the semantics of such kind of Web services? Specifically how can you describe the semanitcs of the geospatial features as input variables, as you know even we have hundreds of different projection types and datums while the x,y couple can be formatted in different ways with varied types of non-spatial attribute fields and values. If there is nothing related to WSDL, then trying to add semantics onto WSDL file whether in bottom-up approach or top-town approach will just waste your time since you almost create a new file to define such comprehensive features that are not included within WSDL. Again I think WSDL just provide an abstract interface that contains the names of the service, functions, input/output variables as well as the associated relationship generated in the process of OOP. As I discussed with Dr. David Mark, in GIS domain, we also need to consider how to define the order of input variables, how to define the purpose of the service and functions as exactly the same functional interface can perform different tasks and generate different results. Such issues will also be a normal problem considering when we try to develop Web services for different kinds of statistical modeling functions. Again, I suggest that semantic Web service research should have a common ground for discussion. If GIS domain is too specific, then we may use statistical Web services for testing and validating each approach. For example, how can we describe the semantics of NISSWebSwap Web service provided by the National Institute of Statistical Sciences (NISS). The service semantics is describe at: http://www.niss.org/WebServices/dg/WebSwap.html and WSDL URL is: http://www.niss.org/WebServices/dg/WebSwap.wsdl One more issue is that I am wondering whether OWL is suitable to describe the semantics of Web services if the purpose of semantic Web services is to help the services requesters (human beings) to understand the meaning of the service while OWL is designed not for human beings but rather for machine to process request and response. Any comments and suggestions will be greatly appreciated. Many thanks again to all of your kind advice and support. I hope we can use some more real world cases to discuss the problems in building semantic Web services other than those intuitive and simple business models. Please forgive me for those straightforward comments and I look forward to your further suggestions. Best wishes, Xuan -----Original Message----- From: Amit Sheth @ LSDIS To: public-sws-ig@w3.org Cc: xshi@GEO.WVU.edu; Juggy.Jagannathan@mail.wvu.edu Sent: 9/7/05 5:42 PM Subject: RE: FWD [Work in Progress on Semantics for Web Services (Advance Notice)] Xuan: I think you need to read the documents more carefully before you comment with such strong convictions. We will limit the comments to the WSDL-S portion of your message. "WSDL-S would only add semantics onto such WSDL elements ..." Looks like you only read a part of the document that talks about "bottom level annotation".. Here is what I suggest: do a search for "top level" (on http://lsdis.cs.uga.edu/library/download/WSDL-S-V1.html) and see what is described following each of the matches. [While we gave running examples for bottom level, I guess we would add examples for top level/bottom up and top down annotations if the document does not become too long; or we will create more appendices.] One comment I sympathize with is that all of us often use simple, almost trivial and pedagogical examples. But then we all want our documents to be readable, right? That's why we need to use tools (such as Radiant for annotating WSDL-S: http://lsdis.cs.uga.edu/projects/meteor-s/downloads/index.php?page=1) and create complex examples. In any case, more complete tools and more complex use cases are coming up... shortly.. and I am sure we will have these before we go too far in adopting any particular approach. Amit Sheth with the WSDL-S team
Received on Thursday, 8 September 2005 02:50:09 UTC