David Price wrote:
> There are of course things that organizations can do to start improving
> the situation, but they have little to do with Ontolog-typical concerns
> and so I doubt that the Ontolog Forum is the place to 'get on with' this
> problem.
>
> I think it's pretty clear now that the OMG cannot do it either - as has
> been proven by the lack of progress on SIMF despite a valiant effort on
> your part. FWIW it's very hard to push through the OMG 'everything is a
> meta-model' and 'vested interests' barriers. Luckily, it seems to me
> that a new language is actually pretty far down the list of important
> mechanisms/approaches wrt information federation anyway.
> (01)
Well, I can agree to some extent. The problem that OMG has in this
regard is that Cory is pushing for a *standard* that supports 'semantic
integration tools', and he can't name one. I pointed out then that, in
spite of 2 EU FP6 projects and millions of euros invested in this, the
result was only weak academic tooling, and the three collections of
tools I saw chose different organizations and different integrating
mechanisms. The OMG Telecomm group put out an RFI for the current state
of the art in semantic integration tools and got only one response, from
Cory's AESIG. NIST itself is now on its 4th project in trying to define
a feasible toolset for some known mediation problems. Part of the
difficulty is in agreeing on what the modules should be and do, and part
of the difficulty is agreeing on an adequate form for the integrating
model. (02)
But the main problem is simply that it is easier to build a one-off
mapping of your business data from representation1 to representation2
using XSLT or Java, than to learn to use, and use, the tools to create
the ontology for your business data and the tools to map the XML schemas
to the ontology and the tools to perform the runtime transformations.
You have to see a broader, longer-term value to the reference ontology
to realize any value at all from the extra work. (03)
And the reference ontology has to be able to capture the rules of usage
that you will write into your XSLT script. OWL can't. RDF can, if the
tool provider invents enough special vocabulary, but what modeling tool
will you use to create the RDF ontology? UML with stereotypes and OCLv2
can, but it isn't any easier to write OCL than Java. So there is a
serious practical barrier to getting /useable/ and /cost-effective/
semantic mediation tooling. And that is why there are not lots of
commercial tools. (04)
Yes, there is enormous value to be realized, IF you can figure out how
to create it. We at NIST justify our work in this area as 'research',
because we have not yet seen a tool set that is even effective, without
getting into useable or cost-effective. And OMG has been given to
understand that the IBM evaluation of the situation is similar. So I
applaud Cory's idea that this could be an interesting topic for the
Ontology Summit, if nothing more than to get a clearer handle on the
state of the art in semantic mediation in 2012. The state of the
practice is nearly non-existent, which is why a standards project is of
doubtful value. (05)
> Cory, this problem belongs in the W3C. I suggested that to you
> previously, and the events of the past year have made that fact even
> more clear in my mind - the solution has to be based in Web and Internet
> standards and technologies. (06)
That is certainly true, but all of OMG, W3C, OASIS and other bodies are
working on solutions to various problems based on XML and XML Schema and
WSDL/SOAP, and all their dialects and add-ons, which is the meaning of
'Web and Internet standards'. Then we come to who is actually working
on solutions using OWL and RDF, and suddenly we have much smaller and
more scattered contingent, but there are active committees in all of
those, and all in various states of disorganization. (07)
I don't see that W3C is a better choice. The W3C RIF project, for
example, had the problem of having to work with OWL and having to work
with SPARQL, because those were the W3C invested technologies, even
though none of the non-academic rules engines, and at most half the
academic ones, had anything to do with either one. (David's employer
falls into non-academic category; TopQuadrant support for OWL was an
afterthought.) In short, going to W3C just begets a different set of
politics and prejudices. (08)
The problem is not what technologies to use, or where to do the
standards work. The problem is to have a community that has semantic
mediation tooling and is interested in getting a standard to enable some
tools to work together. All of the tool sets I have seen perform the
entire mediation function. They need to be able to read XML schemas,
and ASN.1 schemas (in HL7), and EDI schemas (in many business
applications), and EXPRESS schemas (in manufacturing and construction),
and read and write the corresponding standard message forms. They need
to have an internal representation for the integrating model (aka
reference ontology), and they probably rely on some off-the-shelf
modeling tools to provide the input from which that model is created.
It may be advantageous to convert UML to OWL or vice versa, and they
probably need to add UML stereotypes or something the like to mark up
the incoming model to meet their internal needs for the content of the
reference ontology. In addition, they need a runtime capability that is
based on a central engine with interface and schema plugins on the input
side and the output side, and the semantic maps and reference ontology
as inputs. (09)
Now given that you are building a semantic mediation tool suite, you
have a list of tool components (which the last draft of the SIMF RFP was
still not clear on): reference ontology creation tool, semantic mapping
creation tool, general runtime conversion engine, semantic mapping tool
plugins for XML schema, EDI, ASN.1, EXPRESS (according to your target
market), runtime plugins for the schemas and the corresponding data
encodings for input and output, and runtime plugins for WSDL/SOAP and
ebMS, and probably other protocols (again depending on target market).
If you build all the tool components as part of your suite, the only
standards you need are the existing standards for the schemas and the
data forms. (010)
There are already standards for all schemas and encodings, and there are
probably open source libraries for reading both and writing encodings.
Unless you want to standardize the Java APIs for that, there is no
opportunity for standards there. (011)
Similarly, you probably want the reference ontology creation tool to be
some off-the-shelf product of a vendor that does that kind of thing
well, and spits out some standard form, like UML XMI or OWL/RDF or RDF
or CLIF (if John Sowa has convinced anyone). Alternatively, you could
probably use one of these do-it-yourself graphical DSL tools to make
your own tool, and then use your own internal reference ontology format
as the direct output of your tool. In either case, however, you don't
need a standard, unless you need a new language. (012)
Finally, you will need a tool that can take an exchange schema in its
left hand, and a reference ontology in its right hand, and enable the
domain expert to define the links between the model elements, path to
path. This is the critical Semantic Mediation Rules Tool. And you need
to define two sets of links -- one is an interpretation rule: data to
concept; the other is an encoding rule: concept to data. They are not
always symmetric, because the starting points are usually different.
The Semantic Mediation Rules Tool needs to record and export the mapping
rules it generates, because those rulesets are the critical input to the
runtime engine -- the Mediator. If you expect that one organization
will build a Semantic Mediation Rules Tool that can be used by someone
else's Mediator, you need a standard for the representation of semantic
mediation rules. If not, then not. Does any commercial or academic
project not envisage building both the Rules Tool and the Mediator as
part of its toolkit? None that I know of. Why would you? Is there any
reason to create a standard for communication between my Rules Tool and
my Mediator? Not only is it my design choice, it is my IP, and I can
improve my capabilities by improving the capabilities of that interface
whenever I discover a new and exciting feature that I can add. And I
might find it useful to patent my design. The last thing I want is a
standard. (013)
In summary, there is the issue of defining a standard architecture, but
we would have to do that before trying to standardize any of the
interfaces. It strikes me that a useful output of the OMG AESIG would
be the whitepaper that clearly defines the semantic mediation
architecture and assesses the opportunities for standardization, rather
than an RFP for several not clearly necessary standards. (014)
I see only three areas for interface standardization:
- the form of the reference ontology that is input and presented at the
interface between the human knowledge engineer and the reference
ontology capturing tool. It is probably a combined graphical and text
form, a la UML+OCL, or OWL+RDF.
- the form of the reference ontology that is exported by the capturing
tool for use by other tools, including but not limited to the Semantic
Mediation Rules tool and the Mediator. It is probably an RDF dialect.
What all is captured here, or can be captured here, has some impact on
the capabilities and possible behaviors of the Semantic Mediation Rules
tool. So this interface may be an important part of the tool-builder
IP. If there were enough experience to know what all might be useful to
express, you could get agreement on a standard, even though most tools
would only be able to use some of it. Most importantly, however, a
standard in this area that is not just a UML profile, or something the
like, would require the toolsmith to build some kind of back-end for the
off-the-shelf UML or OWL tool that is the primary ontology input tool.
And I would expect that many semantic mediation toolkits might just
assume that a UML or OWL tool can be used and will generate the standard
XMI or RDF formats.
- the form of mediation rules that is input and presented at the
interface between the knowledge engineer and the Semantic Mediation
Rules tool. This is an area that is by no means ripe for
standardization, because the workings of this tool are very different in
various designs. Part of the rules generation process can be automated,
and part of it requires human input, and how much is which, and how the
automation is enabled, and what algorithms it uses, and how complex the
executable rules for the Mediator can be, are all design decisions.
This a primary area of tool-builder IP. (015)
So, IMO, the big question is what the form of the reference ontology
is. Do we need a new language for creating them? Do we need a set of
RDF additions to OWL, or a UML Profile for Reference Ontologies? If we
don't need a new language at all, then we already have all the standards
we need, and we need to get some experience with commercial tools. (016)
If we need a new language, then we also need to standardize its export
form. A UML profile can be processed by off-the-shelf UML tools and the
models can be exported in XMI. Similarly, an RDF add-on to OWL might be
supported by an extension to an existing OWL tool and exported as
described in OWL/full. (Clark/Parsia are already doing this kind of
thing with Pellet.) CLIF may be a desirable export form for some
mediation tools, but it is a highly undesirable input form for knowledge
engineers working with domain experts. Domain experts can glean most of
the content of UML and graphical OWL models with a little experience,
but CLIF is about as intelligible as OWL/RDF or XMI or Old Church
Slavonic. A wholly new language requires a new set of tools and
standards for both ends; a CLIF tool requires a new input form. (One of
the failures of OMG SBVR is that it exemplifies a possibly viable input
form for rules and definitions that it does not standardize, and then
standardizes an output form that merely competes with OCL and CLIF/IKL
-- a new kind of train on existing tracks with no doors for the passengers.) (017)
And at this time in history, I think the standardization of input to the
Mediation Rules generator would be a mistake. There is no agreement on
how to generate such rules, or even what capabilities of the Mediator
they must drive. So, let us by all means have conferences and
whitepapers on the subject, but please not as standards development
projects. (018)
> The Goverment Linked Open Data WG and the
> RDB2RDF WG are examples of practical things happening in the W3C that
> will hopefully make some real progress possible. More of that kind of
> thing, perhaps more focused at this particular problem, seems like the
> only practical way forward to me.
> (019)
Linked Open Data is the latest in a long line of webheaded information
integration technologies, which is in no way related to semantic
mediation, as far as I can tell. RDB2RDF is a knowledge-free technical
transformation of SQL relational database schemas to RDF Schema + SQL
RDF dialect. The object seems to be to allow the implementors of
triple-store databases to use real industrial information that is stored
in relational data management systems in a predictable way. It is
almost the antithesis of semantic mediation, in which the objective is
to relate the database-engineered SQL schema to a knowledge-engineered
domain ontology. But it is the case that some mediation tools take
exactly RDB2RDF approach to the semantic mapping process, and similar
projects use XML Schema as the basis. And let us not forget that Cory
is working the OMG MOF2RDF standard to make standard RDF export forms
for UML models and BPMN models, etc., as RDF Schema + MOF RDF dialect. (020)
This is exactly why W3C is not a better place. I don't think we want
semantic integration standards to be strongly influenced by RDB2RDF or
Linked Open Data, any more than we want them to be influenced by MOF and
SBVR and UML. (021)
I suggest that we can make better progress by getting a whitepaper out
there that identifies the architecture, standardizes a component and
interface nomenclature, discusses the state of the art in mediation
technology and the opportunities for standardization. And I strongly
agree that the Ontolog Summit could contribute to the 'state of the art
in mediation technology' part, which is critical to the assessment of
opportunities for standardization. The AESIG has been so busy trying to
generate acceptable RFPs that it has lost sight of its primary value as
an Architecture Board SIG -- to provide education on the technology and
guidance on the development of a program of work in this area. (022)
-Ed (023)
P.S. In spite of NIST's strong interest in semantic mediation, we
(primarily I, no surprise there) have been a thorn in Cory's side since
the beginning of the SIMF RFP effort. But I believe the suggestion for
a workshop topic for the Ontolog Summit is a much more valuable step, on
the way to the whitepaper that would form the basis for any kind of
standardization plan, and by-the-by serve as a reference terminology for
the emerging papers on the subject. Part of the reason why the EU had 3
different INTEROP projects doing semantic mediation (all differently) is
that none of them used the same terms to describe what they were doing. (024)
--
Edward J. Barkmeyer Email: edbark@xxxxxxxx
National Institute of Standards & Technology
Manufacturing Systems Integration Division
100 Bureau Drive, Stop 8263 Tel: +1 301-975-3528
Gaithersburg, MD 20899-8263 Cel: +1 240-672-5800 (025)
"The opinions expressed above do not reflect consensus of NIST,
and have not been reviewed by any Government authority." (026)
> Cheers,
> David
>
> On 10/27/2011 4:33 PM, Cory Casanave wrote:
>
>> Thanks Peter,
>> I have posted a suggestion on the ontology summit page as you suggested. I
>would also be happy to explore a tread on the topic and have therefor changed
>the title. The initial message, below, can serve as a problem statement.
>>
>> I would like to point out one clear fact: That with all the great work,
>tools, research and products available - the problem of information federation
>still exists and is getting worse. What we have now is either not working or
>not resonating. We don't need and probably can't produce a 100% solution - we
>don't have to. Making a 20% improvement in our ability to federate
>information and exchange data would be of immense benefit to companies,
>governments and society. I think we can do better than 20% and part of that
>is accepting that the 100% solutions are not currently practical. We have to
>make the solution set (of which ontologies are only a part), tractable and
>practical for widespread adoption - that has not been the track record so far.
>>
>> This is a multi-billion dollar opportunity to address a pervasive and
>recognized problem. Let's get on with it.
>>
>> Regards,
>> Cory Casanave
>>
>> -----Original Message-----
>> From: peter.yim@xxxxxxxxx [mailto:peter.yim@xxxxxxxxx] On Behalf Of Peter Yim
>> Sent: Wednesday, October 26, 2011 7:00 PM
>> To: Cory Casanave
>> Cc: steve.ray@xxxxxxxxxx; [ontolog-forum]
>> Subject: [OT] process clarification [was - Re: [ontolog-forum] Some Grand
>Challenge proposal ironies]
>>
>> Cory,
>>
>>
>>
>>> [CoryC] An area of interest to me and many of our clients is solving the
>information federation problem. ...
>>>
>> [ppy] A good topic indeed. However ...
>>
>> 1. if you are suggesting that folks discuss this "information federation
>problem" on [ontolog-forum], please consider starting a new thread (with a
>proper subject line) and move forward from there; or
>>
>> 2. if you are suggesting we (you addressing to Steve, following a remark of
>his regarding the Ontology Summit indicates that this might have been your
>purpose), it would be helpful if you condense the proposition to, say, a short
>theme/title, with a brief (short
>> paragraph) description and post it to the
>http://ontolog.cim3.net/cgi-bin/wiki.pl?OntologySummit/Suggestions
>> page (like what Christopher has done), and then, via a message post,
>highlight that suggestions, and take it forward similarly.
>>
>> (That would help allow this thread to stay on point to discuss what
>Christopher is trying here.)
>>
>>
>> Thanks& regards. =ppy
>>
>
>
> (027)
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