John F. Sowa wrote:
> I came across the ISO standard 704
> for "Terminology work - Principles and methods". ...
>
> That document has some interesting examples, but there are no hints
> of any formal notations. It shows why the terminology of a field
> is important as a prerequisite for an ontology of that field. It
> also shows why there is a large gap between terminology and what
> the theoreticians say about formal ontology.
> (01)
Remember first that the audience for that work is people who write
domain vocabularies, standards of practice and other semi-formal
publications. The objective is to explain to such persons how to select
terms, and conceive and write definitions that will be clear and
understandable to other people who have some training in the subject domain. (02)
Contrast that with the idea of formal ontology, which is about the exact
specification and use of terms in documents intended to be consumed by
automata. The point of the ontologies is to ensure some mathematical
rigor in the specification, because mathematical methods will be
involved in its interpretation and use. That is a very different objective. (03)
That said, as of the turn of the century, there has been considerable
motion in the 'terminology' communities toward formalizing terminologies
as ontologies, as the automata become more intimate partners with humans
in finding information and making decisions. It is important to get the
people and the machines "on the same page". ISO 704 is 30 years old and
in its 5th or 6th revision. The world is moving on, and the TKE
conference is a demonstration that even the old guard of ISO TC37 (the
body that produced ISO 704) are aware of the need to move forward in
knowledge engineering for their trade. (04)
> But I also noticed that the gap between terminology and what a very
> large number of OWL practitioners do is much, much smaller. In fact,
> the overwhelming number of OWL "ontologies" published on the WWW just
> take the informal info from a terminology, put angle brackets around
> it, and call it an ontology.
> (05)
There is certainly truth to that, but as others have observed, just the
limited formalism of defining classes and properties (nouns and verbs)
in a formal way is a step forward. It standardizes machine readability
of the vocabulary terms, and it associates them with some resource that
documents their intent, for the benefit of the human users who will be
working with the machines that to the reading. (06)
Further, this is 'crawl before you walk'. Just getting this degree of
formalism is breaking a barrier. It is making the domain experts aware
that there is information technology that supports what they do, and
they don't need an advanced degree in mathematics or computer science
(as distinct from government, or finance, or automotive engineering, or
habitat management, or medicine) to use it. It should serve to
demonstrate that our fine AI technologies can actually be useful to
them. Their successors will realize that they can add property
definitions and axioms to the ontology, and those additions will improve
its usefulness. (07)
Finally, professional knowledge engineers tend to push OWL to its limits
in supporting automated reasoning. OWL effectively embodies a number of
axiom schemata that support common expressiveness needs. The problem is
that the resulting OWL models are no longer human-readable, or at least
not in the area of the add-on axioms. Most people readily grasp simple
subsumption, but property-defined classes can be (in my experience)
rather difficult for domain experts to understand conceptually, to say
nothing of the ugliness of the OWL representation. (I remember having
to explain the distinction between necessary and sufficient properties
twice, once to a business rules body and once to an engineering
standards body. And I have also presented formalized English sentences
together with the CLIF form generated by a compiler. The reaction of
the audience was: I understand the 'English' and I'm sure glad I don't
have to try to understand CLIF.) What this means is that the more
formal and rich the ontology is, the less accessible it is to the people
whose knowledge was used to create it, and who will be the partners of
the automata that use it. (08)
So, I personally think that the crude ontologies are a demonstration of
'virtus in medio'. There is a lot of current value to the baby steps in
generating domain ontologies. There is a whole community that is coming
to understand what we do at a basic level, and to see what we do as
valuable. We need to encourage them, not disparage their work, or
present them with advanced knowledge engineering stuff that will drive
them away screaming. It won't do to be the 'popinjay bravely born, who
turned up his noble nose with scorn at the loving heart that he did not
prize...'* (09)
> Since I only attended one terminology conference many years ago, I
> would like to ask any Ontolog subscribers who may have more experience
> with the field about their views of the relationship between terminology
> and ontology.
> (010)
We are starting to see several standards for managing 'vocabularies' as
information repositories, e.g., SKOS, SBVR, the draft ISO 11179-3, the
draft ISO 29002, etc. Of these, only SKOS and SBVR understand the idea
of 'definition in a formal language'. For SKOS, of course, the language
is RDF, and the SBVR lot invented their own. The others all have the
idea of definition in multiple languages, but they don't distinguish
natural language text from formal language syntax, because much of their
community concern is having definitions in (e.g.) English and Chinese (a
more traditional 'vocabulary' concern). (011)
It seems to me that an ISO 11179 'terminology' could easily be converted
to a crude OWL model, with the URI referring to the ISO 11179
repository. So, the distance is exactly what John described above. By
comparison, a SKOS vocabulary _is_ an ontology -- it has a standard RDF
form. Whether it is 'crude' or not depends on whether RDF definitions
are common in it. In a similar way, an SBVR 'vocabulary' (or one of its
several packaging concepts) could be converted to an ontology, and the
result will be a crude ontology if all the terms have only English
definitions, or a genuinely rich ontology if most of the definitions
have what they call 'semantic formulations' in their XML representation
of logic. (Their logic includes modalities and nominalization and
Davidsonian treatment of situations, but it has no formal semantics --
it is a grab bag of logic extensions. OTOH, a reasonable subset has a
mapping to CLIF.) And, unsurprisingly, many of the founding SKOS folk
and SBVR folk and a few ISO 11179 folk are co-workers with the
vocabulary standards folks in ISO TC37. So, it is my assessment --
admittedly from the particularly warped lens of standards work -- that
some part of the 'vocabulary' expertise and its products already have
one foot in ontologies. And that is a good thing. (012)
-Ed (013)
* from "I have a song to sing, O!", W.S. Gilbert
> I would also like to ask OWL advocates about those popular ontologies
> whose only "definitions" are English phrases marked as comments. What,
> if anything, do they get from such an ontology that goes beyond what
> they could get from a well-written terminology?
>
> John
>
> _________________________________________________________________
> Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
> Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
> Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
> Shared Files: http://ontolog.cim3.net/file/
> Community Wiki: http://ontolog.cim3.net/wiki/
> To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J
>
> (014)
--
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 (015)
"The opinions expressed above do not reflect consensus of NIST,
and have not been reviewed by any Government authority." (016)
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/
To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J (017)
|