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RE: Where are the semantics in the semantic Web?

From: Shi, Xuan <xshi@GEO.WVU.edu>
Date: Sat, 26 Nov 2005 16:09:46 -0500
Message-ID: <D81F456794C18B4DA3E2ABC47DBBEEF2094E52@onyx.geo.wvu.edu>
To: "'Bijan Parsia '" <bparsia@isr.umd.edu>, "'drew.mcdermott@yale.edu '" <drew.mcdermott@yale.edu>
Cc: "'public-sws-ig@w3.org '" <public-sws-ig@w3.org>


-----Original Message-----
From: Bijan Parsia
To: drew.mcdermott@yale.edu
Cc: public-sws-ig@w3.org
Sent: 11/25/05 4:53 PM
Subject: Re: Where are the semantics in the semantic Web?

On Nov 25, 2005, at 3:34 PM, Drew McDermott wrote:

>> [Shi, Xuan]
>> But where are your viewpoints and suggestions to my discussion in
>> http://lists.w3.org/Archives/Public/public-sws-ig/2005Nov/0089.html
> I think your proposals make perfect sense.  You want to replace WSDL
> descriptions with descriptions of web services with standard names and
> standard argument-result protocols.
Er...can't you do that *with* WSDL? WSDL describes service names and 
argument results protocols. The abstract description can be bound to 
many protocols and wire formats and be realized by many endpoints.

So, er...what's the diff?


You may wish to read W3C's document "Web Services Architecture" at
http://www.w3.org/TR/ws-arch/ and find the definition about service
description and semantics. Here is the quotation for your reference:

1.4.3 Service Description
The mechanics of the message exchange are documented in a Web service
description (WSD). (See Figure 1-1) The WSD is a machine-processable
specification of the Web service's interface, written in WSDL. It defines
the message formats, datatypes, transport protocols, and transport
serialization formats that should be used between the requester agent and
the provider agent.  ... ...

1.4.4 Semantics
The semantics of a Web service is the shared expectation about the behavior
of the service, in particular in response to messages that are sent to it.
In effect, this is the "contract" between the requester entity and the
provider entity regarding the purpose and consequences of the interaction.
...... While the service description represents a contract governing the
mechanics of interacting with a particular service, the semantics represents
a contract governing the meaning and purpose of that interaction. ......

So why do we need to add "semantics" for Web services? Because those
"message formats, datatypes, transport protocols, and transport
serialization formats" do NOT "represents a contract governing the meaning
and purpose of that interaction". 

The efforts of adding semantic annotations on to the abstract WSDL
interface, objects, elements, etc. may lead to the semantic chaos as
mentioned in

sellTicket = buyTicket
buyTicket = buyAirlineTicket
sellTicket = buyAirlineTicket
... ... ... ...

So you see the result and difference?
Received on Saturday, 26 November 2005 21:09:19 UTC

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