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[ontolog-forum] RDF & RDFS (was... Is there something I missed?)

To: <edbark@xxxxxxxx>, "'[ontolog-forum] '" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: "Ian Bailey" <ian@xxxxxxxxxxxxxxxx>
Date: Mon, 2 Feb 2009 21:11:04 -0000
Message-id: <00de01c9857a$d4fdd8c0$7ef98a40$@com>
Hi All,    (01)

Foolhardy as it almost certainly is, I couldn't resist putting my oar in.
I've got the dubious privilege of having implemented one of the early OWL
editors (now a freebie download on my website...sorry Peter, it's not open
source, but that has more to do with the appalling state of the code than
any will to power on my part). I've also been working with the Chris
Partridge / Matthew West 4D extensional ontology approach for a good few
years now, which is pretty far removed from the intent of the SWeb as stated
by Sir Tim and the W3C. Matthew and Chris are looking for a better, more
accurate model of business through extensional analysis. The SWeb, as far as
I can deduce, is doing for data what HTML did for hypertext...i.e. allowing
relationships to go outside the confines of the computer the data sits on.    (02)

If you treat RDF and RDFS as simple modelling syntaxes (that's all they
are), you can use them quite nicely to represent your ontology - even an
extensional, 4D, higher-order ontology. It's less easy to do that with OWL,
as that language tries to be a bit more clever (and as always with things
that try to be too clever, shoots itself in the foot). It's just a syntax -
the semantics should be in your ontology, not in the language you choose to
publish it in. We use UML as the master for the IDEAS ontology. Again, if
you use it carefully (in this case we have a UML profile that exactly
replicates the ontic categories in the IDEAS Foundation), it's fine. Even
more shocking, we use the UML to auto-generate an RDBMS implementation of
IDEAS and an RDF Schema of the IDEAS ontology. These languages are just
tools of the trade. Use them carefully and they'll do the job.    (03)

I'm not wedded to the semantic web. I don't think there is even a common
consensus for what it is. However, don't dismiss RDF and RDFS for that
reason. They're just a neat(ish) way to express your models in XML (be they
data models, ontologies, taxonomies, etc.) that lends itself well to
distributed data. Yes, they use URLs, but if you don't like that you can
always invent a fake namespace and just use whatever IDs you like within
that namespace. To be honest, if I've learned anything from BORO it's that
names are complex beasts, so any attempt to rely on an in-built mechanism in
XML isn't going to get you very far. The ontology itself should model names,
and the RDF simply represents your ontology in a computer interpretable
format. End of.    (04)

All implementation will involve compromise. If you don't think so, you've
never worked on a commercial system. The trick is to implement in such a way
that you do not restrict your ontology's expressiveness. If you can't see a
way to do that in RDF/RDFS, then you probably need a bit more imagination -
hire some engineers instead of computer scientists. RDF and RDFS are not
perfect, and the flaws in OWL are recognised by everyone who has worked with
it. Standards are never perfect. The trick is to stop whining about it and
actually try it - then you start to realise that a few (acceptable)
work-arounds can get you a long way.    (05)

The moral of this story is that you should concentrate on building a good
ontology rather than whining about the languages that can be used to do it.
It's a poor workman who blames the tool.    (06)

www.modelfutures.com    (07)

-----Original Message-----
From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx
[mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Ed Barkmeyer
Sent: 02 February 2009 19:34
To: Pat Hayes
Cc: [ontolog-forum]
Subject: Re: [ontolog-forum] Is there something I missed?    (08)

I think I have to agree that Pat H is right, unfortunately for Sir Tim 
and the "Semantic Web".    (09)

I wrote:    (010)

>> SemWeb is about creating and using knowledge models
>> to mark up documents (and other resources) in order to improve
>> information searches.    (011)

Pat Hayes wrote:    (012)

> No, really, this isn't accurate. The SWeb is about creating and 
> publishing K.models to be used by software agents on the Web,    (013)

as distinct from software agents that are not "on the Web" (which made 
"Semantic Web technology" a brand new technology in 1995, utterly unlike 
the K-R and K-E work of the previous 20 years).  This is precisely the 
funding hype.  If Pat wants to insist that all knowledge engineering 
after 1995 will be called "Semantic Web technology", he is welcome to do 
that, and I will withdraw my objection.  (But then he has to understand 
that the folks who make UML models in OWL to markup their documents have 
just as much right to expound on "ontologies" as any AI expert.  He 
chose his company.)    (014)

I agree that AI's time has come and that standardization of formal 
languages for certain kinds of reasoning engines is appropriate.  And I 
agree that sharing and reusing ontologies is a great idea, if we can 
figure out how.  But that has little to do with the World Wide Web 
(semantic or otherwise).    (015)

My complaint is that the Web is not necessary to, and in many cases not 
significant to, a major part of the development and application of 
knowledge engineering.  Document and service search is clearly a Web 
idea, and the Web is vital to it, and integrating the Web aspects into 
the languages and reasoning engines that have those purposes is 
critical.  There are other distributed applications of ontologies that 
are designed to use the Web in important ways (software agents 
_integrally_  "on the Web", as distinct from agents that just use 
Internet technologies as a means of moving bits from a known remote 
source), but they are a very small part of the applications of knowledge 
engineering.    (016)

> not 
> primarily as document markup. And performing inference from those 
> knowledge models is central in SWeb thinking.    (017)

Performing certain kinds of inferences from knowledge models is why we 
build 'knowledge models', as distinct from other kinds of models. 
Document search (including service descriptions at some level) needs 
certain kinds of inferences, most of which can be performed by DL 
engines.  Decision-making needs certain kinds of inferences that tend to 
exceed the capabilities of DL reasoners.    (018)

When people use the term 'Semantic Web technologies' to mean both, it 
becomes synonymous with "knowledge engineering technologies", which 
covers a dozen distinguishable reasoning technologies of the last 30 
years.  So if there is a distinction, I would like to know what it is.    (019)

>> Most prior knowledge engineering was aimed at
>> facilitating decision-making by automated means.  Those are different
>> ideas, and there is only some overlap in the requirements on the
>> underlying technologies.  In Mike's own terms, "trusting our business to
>> <a knowledge engineering activity>" is NOT a SemWeb concern.
> Wrong; this is exactly what some people are aiming to do. Nokia phones 
> already trust their business to SWeb knowledge engineering, for (one) 
> example.    (020)

So Nokia phones run some OWL/DL-based app that does something useful? 
They run some K-E app that uses the Web in making decisions?  They run 
some K-E app that talks to Nokia servers, or telcomm servers, to make 
decisions?  What does "trust their business to SWeb knowledge 
engineering" mean?    (021)

When I use a K-E app to assign people and machines to tasks that 
directly affect revenue, I'm trusting my business to that app.  When I 
use a K-E app to help choose a medical treatment, by eliminating ones 
that inferentially don't apply, I'm trusting more than my business to 
that app.  But neither of those apps has any clear relationship to the 
Web.    (022)

> I don't mean here to defend SWeb progress or technologies, only to set 
> the record straight on what the SWeb project is trying to do.    (023)

I did mean to defend OWL/DL, because it is very useful for the purpose 
of document markup and much of the inferencing used in document search. 
  That it may be much less useful for other K-E activities that are 
called "Semantic Web" activities by a broadening of the term is not a 
problem with the technology; it is a problem with creating erroneous 
expectations.    (024)

If the "SWeb project" is now the umbrella for all knowledge engineering 
(which I believe is the case), the class "semantic web technology" has 
no useful common characteristics.  And we all need to understand that 
some "SemWeb technologies" will be perceived as useless or misguided by 
people who have a different KE problem.    (025)

I have watched very intelligent people run around painting their roses 
the funding color of the year for 30 years.  They end up competing with 
a bunch of illiterate moneygrubbers with paper roses, because they won't 
agree to a criterion that would eliminate paper roses, if it might also 
eliminate old wood.  And I believe "semantic Web" is now in that state.    (026)

We are seeing, and will see more, apps that speak to other remote apps 
in their operating environment and use the knowledge thus gained, with 
inferencing technologies, to make decisions about working cooperatively 
toward shared and diverse goals.  These things have nothing to do with 
the Web per se, and they need standards to know what constructs mean 
("semantics"), but they have everything to do with knowledge sharing and 
decision making.  And we are inventing terms like SmartCars and 
SmartGrid and SmartBuilding to describe these technologies.  They may 
document their XML schemas using OWL information models, but the 
decision technologies are rules engines -- classical k-e with modern 
communications and processing speeds.  Their apostles do not call them 
"semantic Web" technologies; they have no need to.    (027)

-Ed    (028)

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                FAX: +1 301-975-4694    (029)

"The opinions expressed above do not reflect consensus of NIST,
  and have not been reviewed by any Government authority."    (030)

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