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Potential Gap (WAS Re: [owl-s] communication between web services)

From: Chiusano Joseph <chiusano_joseph@bah.com>
Date: Sun, 19 Sep 2004 13:43:14 -0400
Message-ID: <414DC532.5ACEBB9E@bah.com>
To: Drew McDermott <drew.mcdermott@yale.edu>
CC: public-sws-ig@w3.org

Regarding automatic composition: 

I've been keeping up with a lot of the wonderful work that is going on
not only in this online community but also some of the additional
research that is being done for the automatic composition and invocation
of Semantic Web Services (Sheshagiri and others). I'm beginning to see
an area that I view as a potential gap, regardless of how advanced the
work on automatic composition and invocation of Semantic Web Services
becomes, and I wonder if I might perhaps be overlooking some references.
The area in question has to do with semantically aware relational
databases, and the ability for a Semantic Web Service to request and
obtain automatically the information it requires from a relational
database - which is separate from, but related to, automatic composition
and invocation of Semantic Web Services. 

Here is a scenario:

Suppose we have a Travel Agent Web Service (classic example), and that
Travel Agent Web Service, among other things, dynamically discovers
Hotel Reservation Web Services, trying to find the best bargain(s) for
the traveler. Suppose also that the Travel Agent Web Service accepts
input from a "traveler profile" that is a record in the travel agent's
relational database. This profile lists, in addition to basic
information such as name, address, etc., various preferences of the
traveler (i.e. the features that they desire for a hotel). The Travel
Agent Web Service would, of course, use this information when
discovering Hotel Reservation Web Services.

Suppose now that there is a Hotel Reservation Web Service that meets
various criteria (to include the traveler's preferences), but it needs
to know additional criteria - i.e. criteria that are not carried "on the
wire" for the request (e.g. number of children). Let's also suppose that
this information is included in the traveler profile, but (for whatever
reason) was not passed on the wire. The Travel Agent Web Service could
simply not discover this Web Service because of the criteria mismatch -
or, it could discover it and handle the mismatch. Handling the mismatch
could entail an action by either the Hotel Reservation Web Service or
the Travel Agent Web Service to request that additional information from
the Travel Agent relational database (let's assume that security
settings will not allow the Hotel Reservation to make this request
successfully because it is not a trusted entity, so the Travel Agent Web
Service will do so).

At this point, we need the following to happen:

(1) The Hotel Reservation Web Service must relay to the Travel Agent Web
Service the information that is missing, and
(2) The Travel Agent Web Service needs to obtain that missing
information from the Travel Agent relational database

It is #2 above that I perceive as a current gap - i.e. unless the Travel
Agent relational database is sufficiently "semantically aware" (i.e.
perhaps it implements an OWL ontology whose classes and properties are
mapped to the database tables/fields respectively), there is no
efficient and accurate way that the required information can be obtained
from the Travel Agent relational database.

So my assumption is that no matter how well the automatic discovery,
composition, and invocation of Web Services works on a real-time basis,
unless we have semantically aware relational databases that can handle
requests automatically as described above, we will never realize the
full potential of Semantica Web Services. Is this assumption valid? Is
work being done in the area of semantically aware relational databases
(particularly from the largest database vendors) that I may not be aware

Kind Regards,
Joe Chiusano
Booz Allen Hamilton
Strategy and Technology Consultants to the World

Drew McDermott wrote:
> > [Sam Watkins]
> >
> > Obviously, this requires the author of the mediator to be fluent in =
> > terms of both ontologies in order to conserve meaning.
> > I think it is interesting to find the means of constructing these =
> > mediators without the author having to be fluent in OWL-S (or any other =
> > ontology description language) but just in the meaning of the =
> > ontologies.
> It's difficult to see what you envisage.
> > While this would allow assisted composition using mediators, rather than =
> > fully automated composition, I think this would be a good stepping stone =
> > towards automated composition.
> Fully automated composition would presumably require the computer to
> be as smart and knowledgeable as we are.  That's not going to happen
> in the foreseeable future.
> --
>                                    -- Drew McDermott
>                                       Yale Computer Science Department

Kind Regards,
Joseph Chiusano
Booz Allen Hamilton
Received on Sunday, 19 September 2004 17:44:05 UTC

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