RE: possible SML use cases

Here's my 2-cents on this issue.

 

There are two separate questions:

1.	Does SML support a solution to the first use case "out of the
box"?  No, but then SML doesn't support any "modeling solution" out of
the box.

 

2.	Could SML provide a solution to the problem?  Yes, provided that
a solution could be described in a document or (more ideally from an SML
perspective) by a set of documents.  If the expected means by which the
change of service could be provided in a document, then the document
could be represented with markup and the have an XML Schema.  Ken,
what's missing in the use case is how you think the solution could
be/would be modeled via documents.  What SML provides is the means to
have complex models that are represented via XML instance documents and
XML Schema and Schematron rule documents with possible interdocument
references.

 

 

Kirk Wilson, Ph.D.
Research Staff Member

CA Labs

603 823-7146

 

________________________________

From: public-sml-request@w3.org [mailto:public-sml-request@w3.org] On
Behalf Of Ken Laskey
Sent: Monday, September 17, 2007 10:18 AM
To: Pratul Dublish
Cc: public-sml@w3.org
Subject: Re: possible SML use cases

 

For the first case, assume the following scenario:

1. The consumer makes a request to a data access service.  The consumer
supplies the variables/properties/... for which values are needed and
the vocabularies/semantic models ... that define them.

2. The data access service looks at the request and calls a service to
look for equivalent requests in other vocabularies and sends the data
source and vocabulary information back to the data access service.  The
information could include pointers to processing instructions, say units
conversions, that may be needed to generate appropriate values from the
equivalent requests.

3. The data access service determines which sources to use and retrieves
raw values from those data sources.

4. The data access service calls other services as needed to invoke
processing instructions from step 2.

5. Other processing may be done to assemble a consistent response
payload.

6. The response is sent back to the consumer.

 

In steps 2-5, the data access service (the one the consumer directly
invoked) looks for appropriate sources and identifies appropriate
processing to be performed.  But in step 2 there may be different
sources available (or unavailable) or different options for equivalent
requests when the same consumer request is made next week.  The
processing in steps 4 and 5 may have changed.  While the response may
still be valid, a change in the sources or component services may result
in a response different from if the request was satisfied in an
identical fashion each time.

 

Now sometimes having the new sources or services is exactly what is
needed.  But if the response changes, the consumer needs to be able to
evaluate why it changed.

 

Hope this clarifies my thoughts.

 

Ken 

 

 

On Sep 17, 2007, at 1:36 AM, Pratul Dublish wrote:





Thanks for your interest in SML and forwarding these use cases to the
WG.

In the first scenario, it is not clear to me why you can't guarantee
repeatability across different requests. I can understand the service
returning different data if the data sources have changed, but this
should be fine.  Please help us understand the reasons that prevent
repeatability in this scenario. Right now, I am unable to determine if
SML will be of any help here.

In the second scenario, you should be able to capture the execution
context as an SML model  - defining  schema, inter-document references,
instance documents, and Schematron constraints to capture the execution
context.

SML is basically XML Schema 1.0 augmented with inter-document references
that capture relationships between documents, some built-in constraints
on inter-document references, and Schematron constraints.  If you can
use XML Schema 1.0 and XML 1.0 to capture some aspects of these two
scenarios, you should be able to use SML to capture additional aspects
of these scenarios.

Thanks!
Pratul

 

public-sml-request@w3.org [mailto:public-sml-request@w3.org] On Behalf
Of Ken Laskey
Sent: Saturday, September 15, 2007 6:01 AM
To: public-sml@w3.org
Subject: possible SML use cases

 

I've exchanged email with Jim Lynn and he thought that these looked like
interesting use cases but suggested I post them to this list to get a
better feel for their applicability.

 

So here they are.  Thoughts are welcome.

 

Ken

 

Begin forwarded message:






Date: September 15, 2007 8:45:27 AM EDT

Subject: The execution context of a service interaction is the set of
infrastructure elements, process entities, policy assertions and
agreements that are identified as part of an instantiated service
interaction, and thus forms a path between those with needs and those
with capabilities.

 

Thanks for helping to pull some pieces together.

 

Ivan et al,

 

Regards,

 

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