RE: Definition of "facet"

[I sent this to Leonard yesterday, I meant to send it
to the list...
I think Doug's mail today brought us closer to the
agreement]

-----Original Message-----
From: Aida Slavic [mailto:aida@acorweb.net]
Sent: 26 February 2004 18:18
To: Leonard Will
Subject: RE: Definition of "facet"


Leonard,

I don't think anyone care how things are called as far as
we have the possibility to encode and manage both:
top level categories (?facet) and  subdivisions (?arrays) within those
In one of my mails yesterday I tried to explain why do we need coding
of this structure for managing vocabularies

> Both of these approaches lead me to think that it is useful to use the
> expression "facets" for these groups or ultimate top terms.

I would like to check whether I understood this properly. Do
you suggest that we call simply FACETS the following?:

	from Stella definition applied in thesauri:
	Activities/Agents/Objects/Materials/Organisms/Places/Times

	Mills/Broughton applied in BC2:

Thing/kind/part/property/material/process/operation/patient/product/by-produ
ct/agent/space/time

	Ranganathan applied in CC:
	personality/matter/energy/space/time

	Coates,Lloyd, Simandl applied in BSO:
	tools/operations/processes/parts/objects of study, or product, or total
system

	Universal Decimal Classification (common concepts + facets):
	common concepts: processes/properties/materials/persons/ethnic
grouping/time/space/form/language
	usual facets within disciplines:
things/kind/part/property/material/processes/operation/product/agent/

And that division that comes under these should be called ARRAYS???

If so I can see the following
- advantage
This terminology will easily be understood by people from bibliographic
domain... especially here in UK. Classificationists and those building
thesauri will be at ease with this.

-disadvantage
a)  This kind of terminology/definition is arbitrary and based on assumption
that everyone knows that the facet of this kind is based on the
theory of fundamental/general facet categories

b) as 'facet' is usually defined technically as a result of a division by
a single criterion ..most of people outside bibliographic world expect
that content of 'facet' would be a simple list of mutually exclusive
concepts.

I think the mail I got from P. Murray illustrate well this last point...

<snip>
Implementations of "faceting" grounded in library science often take the
form of subdividing a class by characteristics -- for example:

Persons according to sex and Persons according to family or other kinship
relation (Source: "Facet Analytical Theory for Managing Knowledge Structure
for Humanities," http://www.ucl.ac.uk/fatks/o_person.htm, 04-sep-2003).
People by gender and people by occupation (Art & Architecture Thesaurus
Browser,
http://www.getty.edu/research/tools/vocabulary/aat/hierarchies.html)

"Both of these examples are described as examples of "faceted" approaches.
But I find that these examples are inconsistent with my understanding of
basic principles of faceting and appear not to map well to principles in
development of computer ontologies.

From my perspective, Persons according to sex is already a composite term
(composite subject) -- persons + gender. Same for people by occupation --
people + occupation. Occupation could clearly be a hierarchical facet by
itself.
Of course, in a large general-purpose knowledge-organization system,
implementing a faceted schema using my interpretation might lead to a
substantial proliferation of discrete facets (Human kinship or kinship among
living organisms might be just one; using Relationships as a facet might be
too abstract.). But in business environments, the number of relevant facets
is usually quite manageable -- for example, in a computer software company,
a useful set of facets might include Actions, Business Roles, Events,
Functional Roles, Business Goals, Information Objects, Organizations,
People, Products, Services, and Vertical Markets.

Foskett asserts that an analysis of facets is correct if foci
(topics/concepts in context within a facet) are mutually exclusive -- "that
is, we cannot envisage a composite subject which consists of two foci from
the same facet." (A.C. Foskett, The Subject Approach to Information.) But in
one of the examples above, it appears that you can create the composite
subject male cousins.

In my understanding of faceted knowledge organization, inheritance of
properties is implied in facet hierarchies, but inheritance (especially
inheritance of all properties) is not formally specified in any examples of
faceted classification I have seen. In computer "ontologies," however,
inheritance of properties is usually considered a basic formal requirement:
"Properties become more useful for knowledge modeling when they are
specified at a general class level and then inherited consistently by
subclasses and instances." (Deborah L. McGuinness, "Ontologies Come of Age,"
p. 177, in  Fensel et al, editors, Spinning the Semantic Web.) What do
experts like yourself believe about the role of inheritance in facets?
</snip>

Received on Friday, 27 February 2004 09:28:05 UTC