W3C home > Mailing lists > Public > public-sws-ig@w3.org > November 2005

RE: Where are the semantics in the semantic Web?

From: Jim Hendler <hendler@cs.umd.edu>
Date: Tue, 22 Nov 2005 18:04:01 -0500
Message-Id: <p06230918bfa9537488a0@[172.31.0.192]>
To: drew.mcdermott@yale.edu, "'public-sws-ig@w3.org '" <public-sws-ig@w3.org>

Xuan Shi -
   Let me once again point you to the slides from my XML talk [1] - I 
contrasted Xlink (which is essentially identical to what you propose 
to do for services) to RDF, showing why they are crucially different. 
There's a big difference between what you have below (because I am 
unsure what "roomtype" is and what values are allowed) and 
http://ex.org/hotel#roomtype which could dereference to an RDFS or 
OWL document which would exactly answer that question.  I could also 
then tell if Holiday Inn's "roomtype" and one at some Inn in Japan or 
China was the same thing, or something that might be different -- 
these are not minor differences - the focus on links is crucial to 
understanding the Semantic Web as I said in that talk
  -Jim Hendler

[1] http://www.cs.umd.edu/~hendler/presentations

At 15:32 -0500 11/22/05, Shi, Xuan wrote:
>My suggestion is that service description can be separated from service
>development. Let's describe the service first. Supposed we have such a
>service description:
>
><ServiceRequest>
>    <Service Name="SearchHotelInformation">
>       <Function Name="WebService.Hotel.SearchInformation">
>          <InputVariables>
>             <CheckInDate></CheckInDate>
>             <CheckOutDate></CheckOutDate>
>             <NumberOfCustomer></NumberOfCustomer>
>             <RoomType></RoomType>
>          </InputVariables>
>       </Function>
>    </Service>
></ServiceRequest>
>
>it's then easy to develop such a Web service.
>
>If such service description can be a domain standard, then ALL hotel service
>providers have to follow such standard to develop their Web services in any
>way they want by reading this request document as their starting point to
>process the request (the format of response should be standardized also).
>
>The problem to your "interesting question" is if such developers do not
>follow the standards since we can develop Web services in anyway we want,
>then there may be no automated agent to communiate each other. This was
>discussed as the most difficult level for interoperability in GIS community
>since such people/organization just do not want to share.
>
>If even we cannot reach such a simple domain specific agreement on service
>description, how can we guess the semantics we generated in varied ways by
>logic? Actually, the logic way may be just another standard and agreement
>that enforces developers to follow on. If their actions are formulated
>within the logical inference scope, then you can get an answer. However, how
>can we process any sort of extra actions not within that scope?
>
>Considering that multiple Web services can perform exactly the same function
>by different interfaces/approaches, since they should have the same service
>semantics, adding semantic annotation onto WSDL may not be the right way
>since the objects/elements in WSDL interfaces/documents are different. This
>means the same service semantics will be described in different
>terminologies. Is this the result we want to see? Or, service description
>should be separated from any technology for service development?
>
>
>-----Original Message-----
>From: Drew McDermott
>To: public-sws-ig@w3.org
>Sent: 11/22/05 2:52 PM
>Subject: Re: Where are the semantics in the semantic Web?
>
>
>
>>  [Shi, Xuan]
>
>>  However, if service semantics is developed based on standards and
>>  agreements, then everything is clear and we do not need logic for
>>  matchmaking.
>
>Well, yes, but that takes all the fun out of it.  You seem to be
>saying that human developers, given enough clear information about web
>services, can write any desired program for interacting with web
>services.  That's certainly true.  The more interesting question (to
>me, anyway) is whether there is a point in "generality space" where it
>pays people to describe web services formally enough that automated
>agents can write the programs, or at least play a role in writing
>them.  The descriptions would have to be written without detailed
>knowledge of what program was going to be required, which seems to
>indicate that the notation should be neutral and general-purpose.
>Such notations tend to look like logic of some kind.
>
>Of course, the answer to the "interesting question" may well be No.
>
>                                              -- Drew
>
>--
>
>                                          -- Drew McDermott
>                                             Yale University
>                                             Computer Science Department

-- 
Professor James Hendler			  Director
Joint Institute for Knowledge Discovery	  	  301-405-2696
UMIACS, Univ of Maryland			  301-314-9734 (Fax)
College Park, MD 20742	 		  http://www.cs.umd.edu/~hendler
(New course: http://www.cs.umd.edu/~hendler/CMSC498w/)
Received on Tuesday, 22 November 2005 23:08:57 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Sunday, 16 March 2008 00:11:02 GMT