Citation: Vanda Broughton. A Faceted Classification as the Basis of a Faceted Terminology: Conversion of a Classified Structure to Thesaurus Format in the Bliss Bibliographic Classification, 2nd Edition. Axiomathes. 2008, 18(2): 193-210
This paper develops a faceted thesaurus based on a faceted classification system. It describes the creation of a thesaurus using the Bliss Bibliographic Classification Second Edition (BC2) as the starting point. It examines various aspects of the relationship between the two forms of vocabulary and how these might be resolved to create a truly integrated and interdependent structure that can be managed to some extent mechanically.
For a regular thesaurus, there should be relationship tags like UF (use for), Use, BT (Broader term), NT (Narrower term), RT (Related Term) to control and represent the relationships of vocabularies. To build a faceted thesaurus, term relations should be detected and converted from the hierarchical structure.
1. For relationships in the Faceted Classification
(1) Broader Term (BT)/ Narrower Term (NT) Relationships
Facet structure provides paradigmatic BT and NT relationships. For BC2, every parent is the BT of each of its children. Every child is the NT of its parent.
(2) Related Terms (RT) Derived from Hierarchy
RTs are derived from terms in the same array (sibling terms), and terms not necessarily siblings, but at a coordinate level in the hierarchy.
2. Vocabulary Control in the Faceted Classification
(1) Equivalence Relationships
The conceptual structure of the classification collocates synonyms (equivalent terms within the same class heading or caption). They are converted as equivalence relationships.
For the most part the BC2 schedules observe some stylistic conventions for synonyms. Usually two or more synonymous terms are separated by a comma, and the evident preferred term is listed first.
(2) Compound Terms
When building thesaurus, it may be needed to convert a single term to a compound phrase, because when moving the single term out from the hierarchical structure, more information would be needed to identify or understand it. The rules for when compounds may be included in a thesaurus are very complex, but broadly embrace:
a. Adjectival phrases where one term generates a species or subclass of the other;
b. Compounds where the terms in combination mean something other than the sum of their parts, or where the parts are meaningless when separated;
c. The term is conceptually compound but represented by a single term.
It is clear that the faceted structure of the BC2 terminologies supports the generation of a compatible thesaurus in a number of ways. For example, it allows the precise identification of broader/narrower terms, and sibling and coordinate associative terms. Equivalence relationships are acknowledged through collocation of equivalent or near equivalent terms. BC2 has the potential for syntagmatic relationships to be automatically detected in a populated system.
While the structure is excellent for managing relationships, questions of vocabulary control are only now in the process of being addressed, and it clear that more rigor must be introduced into the formatting of classes if terms are to be handled as effectively as concepts.