- From: Aida Slavic <aida@acorweb.net>
- Date: Tue, 23 Mar 2004 11:20:33 -0000
- To: <public-esw-thes@w3.org>
Alistair, couple of things related to the article in question and XFML and Sense1/Sense2 in case this may be relevant for SKOS > I just read the article [1] that Doug forwarded. I was wondering if you > could help to me to clear something up. This is a library school essay and for me it was very useful as it clearly demonstrated how easy it is to ignore the difference between classification of objects and classification of knowledge - which is a typical for American library schools. But it is very important to pay attention to this as it represents how the term 'faceted classification' is implemented in XFML and how it is understood by many people creating business portals with excellent browsing facets functionality. In this approach "faceted classification" is classification that is fits in your Sense 1 (division according to one principle at the time, hence "faceted classification" is ANY classification that operates with sets of mutually exclusive categories of any kind). Here everything fits nicely as term 'facet' (fr. la facette - little face) is said to be borrowed from a 'diamond' - each facet represents one side or one face of the diamond. (each property is a single face of a multifaced object). With this one gets all the advantages in managing vocabulary using an elegant relational model. If one knows that most widely used American classifications such as Dewey or Library of Congress C. are enumerative classifications and occasionally/often? fail to consistently apply a simpliest logic of division - then it is understandable why many feel necessary to make distinction between: a) messy enumerative structure b)pure taxonomy and c) something called "faceted classification" simply to emphasise that the last one is a logical and consistent in nature and in the same time helps in managing different properties of objects simultaniously (and is likely to be ontologically clean in Guarino's sense and therefore easier to process by machines). Something like 'deux ex machina' on the KOS scene. UK Classification research group, however, reserves the expression 'faceted classification' for knowledge classification only (knowledge about objects and not objects themselves). Here one obviously has more problems to sort out with facets than detergents, beer cans and bottles of wines. For CRG Sense1 is understood to be there anyway and when they attach attribute 'faceted' to some classification they think that besides this basic logical property level there must be a set of fundamental categories (Sense 2) in place. When thesauri embraced 'facet analysis' they paid attention only to the top organizational structure in a Sense2 and ignored Sense1. The reason being the very nature of thesaurus: alphabetical indexing languages do not need detailed classificatory structure for their managment and can work with a rather rough organizational grouping as far as there is some logical principle behind it (mutual exclusiveness). The discussion on what faceted classification is on the facetedclassification mailing list last year agreed on the following (I think): a) if one is creating a classification for objects/entities (bottles of wines, beer cans, detergents, cars etc.) than it is sufficient to have Sense 1 organization structure applied. b) if one is producing classification to classify knowledge about objects both: facets of properties and fundametnal facets above them in order to be able to organize facets themselves. This is because of the complexity that classification of knowledge operates with, dealing with concepts as well as dynamic relationships among them. The conclusion was that XFML is not meant and can't serve for the purpose b) and suggestion was that we should rather look into XTM in order to accommodate the kind of ontology typical for "faceted classifications of knowledge" which operate with fundamental categories (Sense 2: grouping of primitives) as well as with facets in a more technical sense (Sense1: things according to their properties). If we would code Sense 2 only - does this mean that we would undermine the following??? a) the need for knowledge classification to deal with Sense1 and Sense2 b) the understanding and implementation of faceted principle in a Sense 1 in classification of objects (as in XFML) c) the underlying classificatory nature of thesaurus that can be potentially fully coded and may provide better support in vocabulary control and use (thesaurofacet/classaurus) d) Aida > > I have so far come across two meanings for 'faceted classification': > > (Sense 1) > > A set of things are 'classified' according to their properties. > For example > (from [1]) a set of detergents are classified by 'brand name', 'form', > 'scent', 'agent', 'effect on agent' and 'special property'. In > this sense, > each of these properties represents a 'facet' through which the set of > instances can be viewed. > > (Sense 2) > > A set of 'concepts' are grouped according to their most primitive > type. For > example, the concept 'marble' is placed in the 'materials' facet. The > concept 'insects' is placed in the 'organisms' facet. In this sense, a > 'facet' is essentially a primitive class, and every member of a > facet group > is either an instance or a sub-class of that class. > > So my first question is: have I described these two senses > accurately (or am > I missing something)? > > My second question is: are there any other senses of 'faceted > classification' worth considering? > > Finally: if my analysis is correct, these two senses describe quite > different systems of organisation (*). So would it be useful in the short > term to come up with unambiguous names for these two meanings? > For example, > we could refer to sense 1 as 'classification by description' and > sense 2 as > 'primitive classification'. > > Please let me know what you think. > > Yours, > > Alistair. > > > (*) although sense 2 could be viewed as a special case of sense > 1, in which > concepts are classified according to the value of a 'primitive type' > property - i.e. 'primitive type' represents a 'facet' in sense 1! > > [1] <http://www.miskatonic.org/library/facet-web-howto.html> > > --- > Alistair Miles > Research Associate > CCLRC - Rutherford Appleton Laboratory > Building R1 Room 1.60 > Fermi Avenue > Chilton > Didcot > Oxfordshire OX11 0QX > United Kingdom > Email: a.j.miles@rl.ac.uk > Tel: +44 (0)1235 445440 > > > >
Received on Tuesday, 23 March 2004 06:12:30 UTC