Re: Web service definition

Geoff has a point: the initial sentence is grammatically incorrect and 
hence semantically ambiguous. It needs to be rewritten.

Mark has a point that that the interfaces are not necessarily defined in 
terms of messages.

Arguably, Mark also has another point: "transported" may imply that we have 
only a transport protocol (layer 4) beneath, with no application protocol 
(layer 7) in between.

To address these issues, I suggest the following definition:

"A Web service is a software application identified by a URI, whose 
interfaces and bindings are defined using XML artifacts. Its definition can 
be discovered by other software applications via XML-based messages 
transferred by internet protocols. These applications may then interact 
with the web service in a manner prescribed by its definition."

JP

Geoff Arnold wrote:
> 
> 
> On Sunday, August 11, 2002, at 10:56  AM, Mark Baker wrote:
> 
>> Not me.  It's extraordinarily vague, as Paul also noted.
>>
> 
> OK, please tell me exactly how my definition is any more vague than
> the earlier version. Here they are side by side:
> 
> OLD: Definition: A Web service is a software application identified by a
>      URI, whose interfaces and binding [sic] are capable of being defined,
>      described and discovered by XML artifacts and supports direct
>      interactions with other software applications using XML based
>      messages via internet-based protocols
> 
> NEW: Definition: A Web service is a software application identified by a
>      URI, whose interfaces and bindings are defined in terms of XML based
>      messages transported by internet protocols. This definition, which is
>      described using XML artifacts, can be discovered by other software
>      applications, which may then interact with the web service in
>      a manner prescribed by its definition.
> 
> The only difference which might change the semantics (rather simply making
> the thing grammatical and unambiguous: for example, removing the conflation
> of descriptive and active "artifacts") is the deletion of the phrase
> "direct interactions". I don't know what the original author(s) might
> have meant by that term, but most of the possible interpretations
> imply some rather unfortunate limitations on the scope of web services.
> (For example, it might be read as disallowing proxy or broker patterns.)