Online construction of alphabetic classaurus: A vocabulary control and indexing tool

摘要

Classaurus is a faceted hierarchic scheme of terms with vocabulary control features. It is a system of terms having separate hierarchic schedules of the Elementary Categories: Discipline, Entity, Property, and Action, together with their respective Species/Types, Parts and Special Modifiers. Also there are separate schedules for the Common Modifiers: Form, Time, Environment, and Place. Each of the terms in these hierarchic schedules is enriched with synonyms, quasi synonyms etc. The hierarchic schedules constituting the systematic part is supplemented by an alphabetical index of chain entries. Classaurus is used in the formulation of subject headings in general, and in particular, subject headings according to the Postulate based Permuted Subject Indexing (POPSI) language. For the construction of classaurus the POPSI language itself provides guidelines. A set of programs have been developed to construct a classaurus using as input, subject headings formulated according to POPSI language which are enriched with certain codes to denote the different Elementary Categories, their Species, Parts, Special Modifiers and other Common Modifiers of different kinds. The resulting classaurus has hierarchic schedules but terms in an array are arranged only alphabetically. The hierarchic schedules constitute the Systematic part of the classaurus. The system generates an alphabetic Index Part to the Systematic Part, in which for each term its broader terms are kept to its right hand side successively along with a code to denote the schedule to which the term belongs. To find out the position of a term in the Systematic Part, the whole entry for the term in the Alphabetic Part is taken and the sequence of the terms in it is reversed. Using the code for the schedule in the entry, the appropriate hierarchic schedule is selected. The schedule is then searched using the broader terms successively as keys until the term in question is reached, wherein all the hierarchically related terms could be found, including synonyms, quasi-synonyms etc. Both the Systematic Part and the Alphabetical Index Part are printed out for manual reference and also kept as direct access files for ondashline access and ondashth-spot updating and building up of the classaurus while inputting new subject headings formulated for this purpose.