Re: [owl-s] communication between web services

Jean-Michel,

First,  an ontology is like a dictionary: it defines terms in a very 
precise and unique way.  If two web services use different ontologies 
they just do not share a common dictionary, they cannot understand each 
other.  You can have two great mechanics,  one a Inuit the other a 
Greek, unless they find a common language their working together will be 
very difficult.  Web services are not any different, only more messy 
since they are automatic.

Second,  the OWL-S Profile gives a glimpse of the Web service as a 
monolithic thing,  the Process Model allows you to reason about the 
different processes.  For example,  to buy a book you need 1. to give 
the book title 2. select the best book among all the books that have 
been proposed, 3. pay for what you selected.  4. you get the book.  The 
Profiles will tell you that the Web service takes a title and gets you 
the book (it is a book selling service),  the  Process Model spells out 
the steps 1. to 4,  WSDL tells you how to map each step to a message or 
a remote procedure call.

Cheers,

--- Massimo


jean-michel nougayrede wrote:

> Hi,
>
>  
>
> Thanks for your answers. But there are some points where I need few 
> more explanations please ...
>
>  
>
> First,
>
> All the inputs and outputs of the functions of a web service must be 
> defined in some ontology.
>
> But let's imagine that we have two web services which work on the same 
> domain and they want to communicate between each other. But they don't 
> have exactly the same ontology (they don't have the same owl file). So 
> they can't understand each others and so they never can communicate 
> between each other in spite of being in the same domain. Is that what 
> it means?
>
>  
>
>  
>
> Secondly,
>
> The service profile is used to describe the web service in order to be 
> automatically discovered. Service Profile used the inputs and outputs 
> of the function in order to describe the web service. So with the 
> service profile we can find the web service we want in order to 
> execute the function we want.
>
> Then what is exactly the role of the Service Model (or Process Model)? 
> Because all the informations needed by the web service are describe in 
> the service profile. What I understood is that it is used in order to 
> describe what the web service does with the informations (if it calls 
> an extern web service ...). But how this can be used by the requestor 
> if it is automatic? Does the requestor analyse this (during an 
> automatic execution of the web service)? Or does the process model not 
> only used for the description of the web service processes?
>
>  
>
>  
>
> Sorry if my English is not very clear but it is a little difficult to 
> explain. Thanks for your attention.
>
>  
>
> Jean-Michel
>
>  
>
>  
>
>  
>
>  
>
> ------------------------------------------------------------------------
>
> *De :* Massimo Paolucci [mailto:paolucci@cs.cmu.edu]
> *Envoyé :* vendredi 10 septembre 2004 20:42
> *À :* jean-michel nougayrede
> *Objet :* Re: [owl-s] communication between web services
>
>  
>
> jean-michel,
>
> it all depends on the modeling:  you have to be able to encode enough 
> information to distinguish the different cases.  Specifically,  you 
> will have to describe  the sender, the receiver and the address as 
> different concepts then you can say that the function that you want to 
> model would be sendpackage(sender,receiver,address) in which case 
> things may become more manageable.
>
> The view of OWL-S is that the whole set of concepts is used,  strings 
> should never be used directly,  but buried inside concepts so that the 
> semantics of OWL can be exploited.
>
> I hope this is clear,
>
> --- Massimo
>
>
> jean-michel nougayrede wrote:
>
>Hi, thanks for your answer.
>
> 
>
>I agree that process model describe what the web service needs to execute
>
>correctly.
>
>But in my case, let's imagine that the web service B has the function
>
>sendpackage (name1, name2, address). The process model describes that the
>
>function sendpackage need the three arguments name1, name2 and address. But
>
>how the web service A could understand that name1 is the name of the sender,
>
>name2 is the name of the receiver and address his address?
>
> 
>
>What I don't understand is that in the white paper owl-s, it is explained
>
>how the web service must be described but not how an extern web service can
>
>understand this description and use it. Am I wrong?
>
> 
>
>Jean-Michel
>
>  
>