Re: [OWL-S]: Proposal for 1 new control construct

Drew McDermott wrote:

>>>[David Martin]
>>>Here's an initial strawman proposal for this new construct, which 
>>>indicates the use of a Web service that's defined elsewhere.  It's 
>>>syntactically about the same as the "invoke" construct proposed earlier -- 
>>>but it doesn't carry the same implications about what's going to happen where.
>>>
>>>We've been calling one of these things a "Reference" in conversations, but 
>>>to me that's not really very helpful, so I'm proposing  "Use". Other 
>>>suggestions are welcome.  ("Employ", "enact", "execute", "do", "run", 
>>>"apply" ?)
>>
>>[Austin Tate]
>>We are really talking about a more abstract specification of a process as 
>>opposed to something that can be directly invoked with some known protocol 
>>I assume.
>>
>>PIF work (which was the basis for the core of NIST PSL) used a term 
>>"perform" for an activity if that is useful.  It may be sufficiently far 
>>from the lower level direct "invoke" (invocation of a service) to be helpful?
>>
> 
> 
> There are three items we want to distinguish:
> 
> The definition of a process:
>      
>         <Process id="foo" ...>  ... </Process ....>
> 
> The textual occurrence of a process:
> 
>       <Process id="baz" ...> 
> 
>           <Loop>
> 
>               <Perform rdf:resource="#foo">
>                   ...inputs etc.
> 	      </Perform>
> 	  </Loop
>           <Perform rdf:resource="#foo"/>
>  </Process>
> 
> The execution of a process:
> 
>    On 5th invocation of 'baz', the Loop is iterated 27 times.
>    On the 19th iteration, an execution of 'foo' occurs.
> 
> There is/are
> 
>     1 definition of 'foo'
>     
>     2 occurrences, or references, of 'foo' within the definition of
>       'baz' 
> 
>     27 executions of 'foo' within the 5th execution of 'baz'
> 
> I think Austin's proposal is for a synonym of "execution."  I think
> David's question concerned a synonym of "reference."  

Yes, I'm looking for a synonym for what you call 'textual occurrence' 
above.  Most of the candidates (enact, perform, use, do, execute ...), 
unfortunately, can be used (and are used in ordinary usage) either to 
mean your 'textual occurrence' or your 'execution', depending on context.

[Aside: I think this observation about English is related to the fact 
that we don't have such a clear intuition about whether a process is a 
class or an instance.]

Nevertheless, seems to me that "use" or "perform" work perfectly well in 
the examples we've seen lately.


- David

> 
> Note that there is always at most one definition of a process, and
> there is almost always a small number of references to the process,
> but the number of executions can be anything from 0 to ... some very
> big possibly infinite number.  In a case like this:
> 
>     <If>
>        <Iftrue>
>           <Perform rdf:resource="#foo"/>
>        </Iftrue>
>        <Iffalse>
>           <Perform rdf:resource="#foo"/>
>        </Iffalse>
>     </If>
> 
> there are two references, but only one execution per execution of the
> 'If'.
> 
>                                              -- Drew
> 
>

Received on Wednesday, 11 February 2004 16:27:11 UTC