Use and abuse of occurrence RE: [topicmapmail] Are FacetsReally Simple After All?

[Lars Marius Garshol]

* Murray Altheim
| 
| [referring to message posted to SIGIA-L]
| 
| You don't in this message indicate you've grasped much of anything
| about why Faceted Classification is an important metaphor in
| information science, and why it provides much of the backbone for
| library classification schemes.

That is of course entirely possible. If so, it wouldn't be the only
thing I have an imperfect grasp of.
 
* Lars Marius Garshol
|
| And hierarchies fail on several counts in this regard:
| 
| - you cannot type relationships, so there is only a single kind of
|   relationship between the nodes,
 
* Murray Altheim
|
| No, every single facet is a relationship type. There may be a facet
| hierarchy, but the relationship between the facet and the entity is
| typed by the facet relationship. For example, a book can have an
| author facet (perhaps called "hasAuthor"). That's not a hierarchical
| relation. 

Ah, I see. In that case you are no longer talking about what I
referred to as faceted classification, (which may be my mistake).
Used like this FC simply means applying typed properties to
information resources.

I think my point still stands, though, since you cannot with the FC I
described, or with this FC that you describe, say anything much about
the *values* of the properties. That is, you can with a traditional
metadata system say who is the author of a document, but you cannot
say where that person lives, who employs them, what projects they have
worked on, and so on.

* Lars Marius Garshol
|
| - you cannot type the nodes, so a machine can't tell countries from
|   diseases from people from animal species,
 
* Murray Altheim
|
| I have no idea where you got this erroneous notion. Who created a
| rule that says you can't "type a node"? There are acts of
| characterization (which is a form of typing) all over the place in
| FC. DCMI has an entire type vocabulary. Those types are precisely
| for disambiguation of resource by country (e.g., from
| "http://purl.org/dc/terms/RFC1766"), people (as by creator, or even
| by educational level, as in
| "http://purl.org/dc/terms/educationLevel"). And a more generalized
| FC system could certainly classify by disease, or whatever you like.

That's not what I mean. I'm saying that you can't assert that the
author of poem X is a software program, while the author of poem Y is
a human being. You could assert that poems X and Y are poems, and that
book Z is a book, but again you cannot describe the values assigned to
the properties, only the things given properties.

Of course, if you use RDF you can do this, but I wouldn't describe RDF
as Faceted Classification. Again, that may be my mistake. I'll look at
the references you gave to see if that will help me.
 
* Lars Marius Garshol
|
| Obviously this doesn't give you much power to model the real world,
| and equally obviously facets do not solve any of these
| problems. (You could theoretically solve the second problem with
| them, but I doubt that would work well in practice.)
 
* Murray Altheim
|
| I would have to disagree on "obviously", 

Actually, I think where we disagree is on what FC is.

| and I am currently using FC to solve a real world problem. 

Well, I certainly wouldn't claim that FC can't do that. It has done so
and will continue to do so.

| In fact, I believe that FC is very similar conceptually to frame
| systems (facets and their role in the system are not unlike slots),
| from which a huge number of successful knowledge-based systems are
| constructed or derived.  The facets become the primary means of
| navigating the content, where you can obtain all entities having a
| specific facet value, such as "author:Durrell, Lawrence", "edition:
| 1st", or in a more generalized system (such as Ceryle), "eyecolor:
| blue", "birthplace: New York", etc.  FC becomes the primary
| metaphor/means of organization, searching and navigation. This fits
| nicely as a layer on a Topic Map system. This is not conjecture: I'm
| doing it.

Well, described like this TMs just seem like one of many ways to do FC
implementations. That's not what I thought FC was when I wrote the
email you are quoting, though.
 
| For more information on FC, and especially FC in use in KBS, [...]

I guess the last one is the one that is most relevant to what FC has
been used to mean within the library community. Anyway, I'll look
through this stuff once I'm online again and can actually look at
them.

-- 
Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
GSM: +47 98 21 55 50                  <URL: http://www.garshol.priv.no >