Faceted classification and logical division in information retrieval

Library Trends, Wntr, 2004 by Jack Mills

The particular notion of the fundamental forms of knowledge that underpin main classes has received significant attention by Langridge (1976), who has drawn extensively on the work of a number of philosophers, particularly that of Hirst (1974) and of Phenix (1964) in the philosophy of education. Of particular significance is the distinction Langridge draws between the forms of knowledge on the one hand and the objects of knowledge (the phenomena they examine) on the other The order in which main classes might appear became a particular focus of attention in the work of Bliss (1929, 1933), and a modified form of the general order he advocated is considered in Section 5.2.

A common criticism of the viability of any schema of universal knowledge is that the interaction of existing fields tends to dissolve their boundaries. While this interaction and its tendency are indisputable it does not invalidate the search for relatively permanent structures. Work on BC2 (Mills & Broughton, 1977-) has not found the great waves of new specializations an insurmountable obstacle. With enduring principles like gradation and integrative levels, together with highly practical principles such as the subordination of means to ends to reflect the concept of purpose or end-product to determine citation order within a given class (see Section 8.2), the predictability in the location of quite intricately mixed specializations is ensured. For example, modern forensic science draws on chemical analysis, molecular biology, and any number of medical specializations, but the purpose it serves--to validate the evidence in legal processes--determines its location in the law class with high predictability.

5.2. Two modern general classifications

The Colon Classification (Ranganathan, 1960) is not included here; its significance is primarily that it pioneered faceted classification and provided an experimental test-bed for its development. But its main-class order is quite conventional and offers no solutions to the problem of general classifications per se. The Broad System of Ordering (1978), or BSO as it is usually called, was first designed as a switching language--i.e., an intermediary through which other classifications could translate into each other. Its lack of detail stems from the fact that it was initially based on an institutional warrant--i.e., of subjects displaying institutional organizations underpinning them rather than on the much larger literary warrant of library collections. One feature is the break it makes with the generally recognized fields of knowledge, e.g., it has separate general classes for important concepts normally distributed under different contexts, e.g., Communication and information, Management, Human needs. It also has a Phenomena class (see Section 5.1) for works that cannot be accommodated in any of the largely disciplinary main classes, which are in BSO all fully faceted. It has also been very influential in the development of the next system, BC2.