Wynar, richiamato da Phil Murray, descrive così la classificazione a faccette:
A faceted classification differs from a traditional one in that it does not assign fixed slots to subjects in sequence, but uses clearly defined, mutually exclusive, and collectively exhaustive aspects, properties, or characteristics of a class or specific subject. Such aspects, properties, or characteristics are called facets of a class or subject, a term introduced into classification theory and given this new meaning by the Indian librarian and classificationist S.R. Ranganathan and first used in his Colon Classification in the early 1930s.
Un’ampia definizione di “facet analysis”, tratta da Vickery (1960: 12-13), è fornita da Kathryn La Barre (18 dicembre 2002).
The sorting of terms in a given field into homogeneous, mutually exclusive facets, each derived from the parent universe by a single characteristic of division. Facet analysis is partly analagous to the traditional rules of logical division, on which classification has always been based. The result, however differs from traditional classification in the following ways.
First: The strictness with which the rules are applied: in the analysis performed in order to construct a scheme every distinctive logical category should be isolated, every new characteristic of division should be clearly formulated, every new relation should be recognized *even though at a later stage it may be possible and advisable to present a less refined analysis*.
Second: …facets so distinguished are not locked into rigid, enumerative schedules, but are left to combine with one another in the fullest freedom, so that every type of relation between the terms and between subjects may be expressed.
Third: (From the theoretical point of view) FC breaks free from the restriction of the traditional classification to the hierarchical, genus-species relation: by combining terms in compound subjects, it introduces new logical relations between them, thus better reflecting the complexity of knowledge [and I insert here: whatever universe for which you are attempting to provide access].
Facet analysis by means of fundamental distinguishing characteristics or *categories* is the basic operation in constructing a faceted classification.
Although the faceted classification is regarded by many as a structure with specific characteristics, essentially facet analysis is a technique, and different models of the same universe of discourse can be derived to meet different local or subject-specific needs using different categories and variations on the syntax.
L’italiano Claudio Gnoli (2 gennaio 2003) aggiunge una importante precisazione:
_faceted classification_ has been usually translated by Italian librarians into “classificazione a faccette”: however, as pointed out by my friend Eugenio Gatto (a deep scholar of Ranganathan’s work), _faccetta_ does not mean in Italian the same as _facet_ in English; he would prefer to translate _FC_ by classificazione multidimensionale… and interestingly, Giovanni uses just these words in his description of dynamic taxonomy!
Il concetto di classificazione multidimensionale richiamato da Gnoli assomiglia in effetti molto da vicino ai sistemi di tassonomie dinamiche su cui lavora Giovanni Maria Sacco; vedi:
- G. M. Sacco, Dynamic Taxonomies and Faceted Search