question about "Semantic Annotations for WSDL"

Here is an important question about the proposed "Semantic Annotations
for WSDL" working group, about which I'd love to see some discussion.

The current draft charter is here:
   http://www.w3.org/2005/10/sa-ws-charter.html

Question:
     Does the envisioned approach provide a foundation that will be
     useful in working with, or evolving to, a more comprehensive
     framework, or simply a detour that will ultimately fall out of use
     (if Web service semantics become important)?

What's behind this question is the observation that, from a
WSDL-centric perspective, the semantic artifacts referenced by a WSDL
spec will be disconnected.  That is, from the point of view of a WSDL
tool, they won't exist in the same declarative scope. (Indeed, in this
approach there is *no* notion of declarative scope for the semantic
artifacts, from the WSDL perspective.)

One way to illustrate this concern is simply by observing that
preconditions and effects associated with services will frequently
have variables in common.  To have a coherent representational scheme,
it is of fundamental importance to spell out the relationship between
variable X mentioned in a precondition and variable X mentioned in an
effect expression.  From the perspective of a WSDL tool, there won't
be any basis for establishing or working with such a relationship.  So 
the concern here is that a WSDL tool ultimately won't be able to do much 
with the semantic declarations that are referenced.

Of course, the semantic framework underlying those declarations may
provide the basis that ties the semantic declarations together, and a
WSDL tool could build in some understanding about one or more of the
semantic frameworks that may be used in connection with WSDL.  But the
point is that it's not a WSDL tool anymore - it's a WSDL tool plus a
{UML or OWL-S or WSMO or SWSF or METEOR-S or ODESWS or ...} tool.  And
as far as I can tell, there won't be any meaningful connection between
the two tools.  The concern is that the proposed approach does not
appear to provide any path by which such a meaningful connection might
eventually be achieved.

Cheers,
David Martin
SRI International

Received on Monday, 27 February 2006 23:59:50 UTC