RE: Semantics of WSDL vs. semantics of service

Xuan, 

the problem is that Web Service interfaces are not so well standardized
as electrical plug interfaces, and that's because there's a plethora of
functions that are provided by Web services, as opposed to the one
function provided by the electricity company.

In particular, I don't expect that the interface of my stock quote
service should match the interface of your address lookup service. Even
if the operation is the same (doService(String):String), we will differ
on the data formats and on what we actually perform. WSDL describes the
data formats and WSDL-S tries to point to a description of what we
actually perform.

I'm afraid you have a simplified or idealistic view on what Web services
(should) look like.

Jacek

On Mon, 2006-03-20 at 09:56 -0500, Shi, Xuan wrote:
> It seems you all just ignore the title of this thread as "Semantics of WSDL
> vs. semantics of service" and Bijan just could not answer my question to him
> as why do I need to care about how many bindings he
> has for one operation? Or, why do I need to understand the semantics of his
> WSDL document?
> 
> Given a simple example, we are all the consumers or service requesters of
> certain electricity company. Do we need to care about the infrastructure and
> the framework of the electricity company before we consume such service? Do
> we need to care about how many bindings the electricity company has, and,
> how they switch to any other bindings to maintain its operations to support
> the service it provides? Definitely not!
> 
> As service providers, can we give more consideration for our service
> requesters? We can consume the electricity in the same interoperable
> appraoch because every plug and receptacle are all standardized. In that
> way, the service requesters do not need to care about your complex
> infrastructure, framework, logics, etc. People access "Web" services in the
> same situation.
> 
> So, please encapsulte all troubles into your server side development.
> Service requesters only need one standardized receptacle so that they can
> use any interoperable plug to consume the service with little question. They
> don't need to know how many bindings you have to maintain your single
> operation. We are service providers, not trouble makers.
> 
> -----Original Message-----
> From: Bijan Parsia
> To: Jacek Kopecky
> Cc: Carine Bournez; public-sws-ig@w3.org; Battle, Steven
> Sent: 3/20/06 8:09 AM
> Subject: Re: Semantics of WSDL vs. semantics of service
> 
> 
> On Mar 20, 2006, at 5:39 AM, Jacek Kopecky wrote:
> 
> > Hi Steve,
> >
> > while the charter does not directly support embedded semantic
> > annotations, I think the issue is still open and up for discussion by
> > the WG.
> 
> I went back and looked and the Scope section is a bit broken (as 
> evidenced by Steve's quote):
> 
> """The Semantic Annotations for WSDL Working Group is chartered to 
> define one or more properties of WSDL 2.0 components to point to 
> additional semantics to concepts represented by those components, e.g. 
> interface, operation, endpoint. Additionally, the Working Group may 
> define annotations to the schema structure to point to external 
> semantics.""""
> 
> "point to additional semantics to concepts" just doesn't parse. 
> Additional semantics *for* concepts represented?
> 
> I confess to hating the term "external semantics". C'mon.
> 
> > I for one see some use cases where embedding the annotations would be
> > useful, and I can see at least two ways of embedding them: put a whole
> > semantic description
> 
> I go back to a fight I had in SWSL. What's a *non* semantic description?
> 
> >  document somewhere in the WSDL document (like we
> > put schemas in the <types> section) and then the annotations will
> point
> > into the document; or put the full annotations themselves on the spot,
> > instead of referring to them.
> 
> How are the "semantics" to be realized? Via some sort of statement 
> (e.g., axioms in some formalism). So let's say I have a set of concept 
> and property names, but no further axiomization. And I want to say of 
> some operation that is has at least one P relation to a C. Now since 
> there *is* no other axiom, this characterized the terms entirely (thus 
> far). May I inline that? It seems like I should be able to. 
> Alternatively, I could require that I always coin a name for these 
> intermediate expressions (but why?).
> 
> (Note that originally I interpreted the discussion as requiring *all 
> parts* of the annotation to be outside the WSDL document, a la OWL-S. 
> There are reasonable reasons for doing this (including supporting third 
> party and alternative annotations seamlessly. Technically, I guess this 
> is not ruled out by the current charter since the concrete syntax of 
> the component properties could be or be required to be in a separate 
> document.
> 
> > While the second option can be seen as out of scope as defined in the
> > charter, at least the first option should be available to us. 8-)
> 
> I find the Out of Scope more disturbing:
> 
> """discuss expression of Web services constraints and capabilities, 
> including precondition and effect."""
> 
> Why? And how can this be at all narrowed? I mean, from the scope, " 
> could have different meanings: calculation of tax on a product, 
> calculation of income tax, etc. " Aren't these expressions of 
> capabilities? (I recognize that constraints and capabilties are a term 
> of art standing for "policy", but still.)
> 
> Cheers,
> Bijan.
> 
>

Received on Monday, 20 March 2006 16:47:34 UTC