Re: Internet/Distributed Computing using HTTP/POST: Bridge semantic W eb and Web services under the same Internet protocol

On Jan 20, 2006, at 8:16 AM, Battle, Steven Andrew wrote:

> Xuan,
> OK, I agree with the staging; that SOAP web-services resolve interop
> problems syntactically (no mean feat by the way if you remember CORBA),
> and WSDL (once you drop out of RPC mode) doesn't make it easy to figure
> out the inputs and outputs in a big lump of schema.
>
>> From here on in, my comments are going to be largely critical, but
> hopefully constructive.
>
> You say that, "OWL-S, WSMO, and others emphasize the process model for
> service aggregation". I don't think so. This comes down to a confusion
> of terminology. OWL-S cannot compose services, only processes that
> ultimately break down into atomic processes that correspond to WSDL
> operations. In other words, OWL-S only addresses compositions of 
> actions
> that can be performed at a _single_ service interface.

I don't believe that at all. Or, to try to make the latter part of your 
last sentence true, since my service interface might call out to other 
service, and OWL-S describes how I do that, OWL-S certainly can....

> It can't
> describe, for example, how you can buy a book on Amazon then sell it on
> eBay because these are two different services.

Do this.

I mean, we have constructive existence proofs!

[snip]
> You say that, "the service aggregation process does not provide the
> semantic meaning of the services and such aggregations should not be
> exposed to the service requesters who are waiting for an answer to 
> their
> request". I think you've misunderstood the subtlety of OWL-S process
> modelling. An OWL-S process does not expose anything going on behind 
> the
> service interface, rather "it is a specification of the ways a client
> may interact with a service" see
> <http://www.daml.org/services/owl-s/1.1/overview/#5>. In other words,
> every step of a composite process has to be performed by the client.
[snip]
While I think that's way too strong (and have argued against what I see 
as an artificial restriction in the text), even granting this 
undermines your earlier assertion. (Plus, it can't be that I *perform* 
the action, in most non-technical uses of perform and many technical 
ones...the client *invokes* it...and with a simple process I don't see 
why it could transfer control).

Cheers,
Bijan.

Received on Friday, 20 January 2006 14:07:31 UTC