[Sigia-l] Facets vs. ontologies [was: Sigia-l] Findability - hierarchies

[Travis Wilson]

At 08:11 AM 1/30/2003 +0100, Lars Marius Garshol wrote:
>Admittedly you have to be a grammatologist (or crazy) to care about
>any of this, but don't see that faceted classification even allows you
>to dream of doing stuff like this.

I must disagree. You just have to dream in a different color. Faceted 
classification is a different model for doing roughly the same thing, and 
I'll proceed to demonstrate. Yes, topic maps mean:

>it lets you build *very* rich navigational interfaces. From
>any concept you can move in any number of dimensions.

But faceted classification is designed for the same purpose. Your example 
of the Latin script is a good comparison. In a topicmap ontology,

><URL: http://www.ontopia.net/i18n/script.jsp?id=latin-s >
>Here you go to the Latin script. From this point you can go to the
>type of script it belongs to, the category of scripts it belongs to,
>the writing direction it uses, the script it was derived from, see the
>entire family tree, the languages written in this script, to the
>transcriptions from other scripts/languages to this one, as well as to
>resources with more information.

In a faceted scheme: type, category, and writing direction are all facets 
that describe different characteristics of the script -- characteristics 
that are independent from one another. A browsing technology like FacetMap 
lets you move, as you say, in any of combination of those dimensions. The 
FC data model is just as fluid as topic maps if you apply it the same way. 
Just think of each relationship type as a facet. You can list all the 
scripts that are resources under, say, the "Alphabet type" heading, or you 
can combine headings from different facets and list their shared resources. 
Or you can move from one script to another, along any facet -- type, 
category, or writing direction.

Let's cover the rest of the relationships of the Latin script resource. 
"The script it was derived from" is just a different peek into the 
"category" facet; "Etruscan" is a child node of the category "Greek script 
family" and therefore the former implies the latter.

But the remaining relationships are more interesting. How would an FC 
scheme map the languages, transcriptions, and external links associated 
with this script? So far we've regarded the script as the resource, to 
which the type, category, and writing direction facets are mapped. To 
handle these new relationships, we now have to regard the script as a 
facet, and regard the languages, transcriptions, and links as resources. 
Then the new resources are classified with the "Latin script" heading in 
the "script" facet.

For some purposes, the Latin script is a resource; for others, it is a 
heading in a facet. This isn't an unusual phenomenon in the real world.

At this point it could even be argued that such a faceted scheme is MORE 
strongly typed than an ontology. The ontology is kind of a catch-all for 
every type of relationship. FC, on the other hand, forces you to specify 
which end of the relationship is the descriptor, and which is the 
descriptee, like in this example.

Travis Wilson
Development
http://facetmap.com