[Sigia-l] Topic maps and IA
Jonathan Broad
jonathan at relativepath.org
Fri Mar 26 11:27:03 EST 2004
On Mar 26, 2004, at 4:02 AM, Listera wrote:
> "Jonas Höglund" wrote:
>
>> Does anyone have any input to this?
>> * Is it doable?
>> * Is the technologies and the methods behind them developed enough?
>> * Is there enough of skills and tools developed?
>
> Depends on where you're coming from.
>
> If you're new to relational databases and creating data structures, you
> might think all this stuff was invented in the last few years.
>
> The basic notion of creating a virtual abstraction layer to have
> disparate
> systems talk to each other indirectly has been around for many, many
> years.
> A lot of this stuff is old hat to folks who have been doing virtual
> file/storage systems, data mining, system integration through virtual
> APIs,
> etc.
>
> Terminologies may be different but the fundamental notions of relating
> and
> intermediating data structures is pretty ancient, hence my earlier
> comment
> about not reinventing the wheel if IAs want to build bridges to other
> professionals.
>
With all due respect, OWL and topic maps are not the same kind of thing
as a relational database. They're all data abstractions, true, but
they function at a fundamentally different *level* of abstraction.
Also--let's give Lars credit, at least, for making quite a good effort
for using the decades old language of thesauri in an effort to explain
the significance of TMs and ontologies (which have quite a history in
their own right).
I think your point, which is well taken, is that there isn't anything
you can do with topic maps/ontologies (treating them the same at the
moment) that you can't do with relational algebra or custom data
structures. That's true. Well, I think there are some things you can
do with a proper constraint language like OWL that you can't do with
relational algebra, but my predicate logic skillz are too feeble to
prove it. But by that same token, you can do anything with a series
of flat files that you can do with a full-blown RDBMS, given enough
custom programming.
Just as an RDBMS sits on top of a set of flat files and imbues them
with the magic of seamless complex joins, so too a TM system can sit on
top of a RDBMS and manage the schematic and semantic relationships of
the underlying data. Topic maps are in that way like SQL, which served
to standardize the *model* which RDBMSs should conform to, while
leaving implementation up in the air. SQL is data-oriented. Topic
maps (and RDF/OWL) are
information/knowledge/please-don't-nit-pick-oriented. I think that,
should Topic Maps ever 'catch on', they will be to IAs what RDBMSs were
to data managers in the 70s--not because they were impossible in the
60s, but because they were too freakin' expensive to custom-build and
maintain.
The most commonsensical benefit to Topic Maps that I've been able to
come up with (in conversation with DBAs) is that TMs allow you to alter
relationships without having to touch the data (destroying and
recreating tables with a new schema), and allows you to maintain
multiple "views" of the data without needing to duplicate the data with
different schemas. RDBMSs couple the handling of data definition and
data manipulation under the hood. This is great, for one kind of use
of data (where schemas are quite fixed). It's just not as helpful when
you want more complex and various access to the data, which is often
the case when the data is actually human-oriented information.
This is my understanding, anyway. The terminology you object to isn't
new, it's probably the longest part of the history of artificial
intelligence research. I'm just excited because, at long last, we may
be nearing practicable systems for managing knowledge, not simply data.
Jonathan
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