----- Original Message -----
Sent: Thursday, January 30, 2003 1:32
AM
Subject: [topicmaps-comment] back to the
lists
"Dear Oasis TM community"
as a silent-for-months member of TC pubsubj and TC geolang, I
feel that I owe you a statement about my (dis-) appearance.
Shortly after XML Europe last May, I had to focus (to earn my
living) on finishing an R&D project "Semantic Network Services (SNS)" and
on some company-internal work on KM and metadata. I followed the TM
discussion, at least kept track of the topics, and sometimes I was making up
for a posting, but - I still was somehow undecided ("mixed feelings", 2002)
about some basic issues, and I did not find a clear position fast
enough.
Now, SNS has been completed (at least more or less), and I
start to look over the surface again (...is this German lingo? ...)
Last week I attended the "Open Forum 2003 on Metadata
Registries" (http://metadata-stds.org/OpenForum2003/) in Santa Fe,
arranged by ISO/IEC JTC1 SC32 WG2 (http://metadata-stds.org/). I followed and presented-in the
"Terminology and Ontology" track, and this gave me the final inspiration to
re-enter the discussion.
In (relatively) short:
++++++++++++ 1.
Generally, discussion of TM should be more in the context of what's happing
outside in the world of metadata, ontology, etc. As I have been confirmed once
more in Santa Fe, there are many contiguous applications for TM fitting into
open ends of related standards like ISO 11179, ebXML, UDDI, and Semantic Web -
but people don't really know about us - though most of them are curious about
our possible contribution to the game.
On the other hand, there are several approaches out there that
might be adopted for open issues of our own world, like OWL, or the Extensible
Resource Identifier (XRI).
++++++++++++ 2. PSI
Every metadata
initiative in the world is highly interested in a well defined terminology for
values, which PSI can provide. The most important thing is that there really
need to be unique and persistent URI for any of the controlled terms. I think
it is of less importance, to what these URI really point. All the variants
mentioned in http://www.oasis-open.org/committees/tm-pubsubj/docs/recommendations/general.htm
must be supported, as they are real.
The most important pre-requisite for PSI to go live are:
organizations that maintain them, in whatsoever form. ISBN work sufficiently
(when did you order a book last time?), as there is a strong and sustainable
organization behind them.
It has been clearly agreed that we will not maintain PSI-sets
ourselves as a service. So, what is our contribution?
To my opinion, machine-readable PSI will play the strategic role in the
future (no problem for a machine to convert e.g. XTM into human-readable
HTML).
There are (at least) two related approaches that we should
include into our considerations, if we don't want to finally find ourselves in
a maverick position ("small boats" are not necessarily faster, Robert
:-):
a) The handling of taxonomies in ebXML and UDDI (google for
"taxonomy" and one of the organization acronyms). We must fit into that and
find our "added value".
(I am sure there is ... the concept of Topic Map is a valid
template in the vague world of Ontology ...).
b) OASIS
Extensible Resource Identifier (XRI) Technical Committee. http://xml.coverpages.org/ni2003-01-08-a.html - why aren't
we in this boat? XRI is closely related to PSI, and we should get into this
discussion.
Karl Best had a very generic talk at the Open Forum (not yet
on-line today). He did not mention TM at all. But he was presenting a new
cross-organization standards registry initiative (kind of extended xml.org -
his slides will be on-line soon ...), and there was a slide showing something
that looked like a topic map. Why didn't he propose it to be one? Diplomacy?
Or doesn't he take us as a serious option? (see the related OASIS RFP at http://www.oasis-open.org/documents/registry_rfp.pdf).
++++++++++++ 3. What interests me most, currently, is OWL (http://www.w3.org/TR/2002/WD-owl-guide-20021104/). In my
project work over the last two years I found serious deficits in the
XMLization of the topic map concept.
One simpler thing is that there is no normative XML Schema for
topic maps. If you want to use TM in a context like web services, any of these
today require an XML Schema to be integrated. It's easy to load the XTM DTD
into XMLSpy (or something) and convert it - needs some human cosmetics to get
it to work, but not too much - but that's not normative! There have been lots
of discussions about a TM Schema that I don't want to rehash - would be enough
to make it semantically as equivalent to the DTD as possible -agreed, and
"official".
What's more crucial is the lack of a serialized formal
definition of the typology and constraints of a given topic map instance, such
as which topic types may play which role in which association in this domain
(natural lingo: "A string quartet consists of exactly 4 bowed string
musicians: typically 1st and 2nd violin, viola, and cello"). Something like
this was announced (http://www.y12.doe.gov/sgml/sc34/document/0323.htm) to be
addressed in "ISO 19756: Topic Maps Constraint Language (TMCL)". Public
discussion of further work has finally started one week ago at http://groups.yahoo.com/group/tmcl-wg/. Great!
Reading the Web Ontology Language (OWL) development at
http://www.w3.org/2001/sw/WebOnt/, I highly suspect that TM
schema definitions can be completely written in OWL by defining classes like
<tm:topic> as a subclass of <owl:thing>, and so provide the TM
concept as an implemented OWL "library" schema that can be incorporated into
any work of the Web Ontology movement. (May be integrate OWL-Wine and TM-Beer
... who'll be doing the non-alcoholics ?).
Regards,