Subject Cataloguing. National Subject Authorities

Subject access in online environment

Advantages of authority control in current information environment

In order to make subject analysis process more efficient, easier and faster in current online environment, it is necessary

· to prefer postcoordinated procedure

· postcoordinated language can provide the same precision as the precoordinated one, when including equivalent notation of a classification scheme into the retrieval process to avoid “false drops”. In addition, a notation of classification scheme gives a context to the verbal search term.

· to simplify application syntax

· to improve online display of assigned subject headings

· to facilitate automatic validation of subject headings and automatic maintenance of subject authority files

· to reduce the size of authority files

· to support conceptual compatibility of indexing formulas/preferred terms used in various indexing languages

· to support harmonisation between various indexing languages (multilingualism issue)

· to support mapping between verbal terms (indexing formulas) and equivalent notations of classification scheme

· to improve hierarchical structure of subject authority file

· to make the assignment of controlled terms more efficient

· to enhance and encourage co-operative cataloguing efforts

· to improve subject access for OPACs

· to improve subject access for Web resources

The role of the classification scheme in online environment

Advantages of a universal classification system in online environment have been enumerated

Universal classification scheme applied in networked environment can enhance subject access because it

· covers all subjects

· is able to create collections of related resources in a hierarchical structure quickly and easily

· improves subject access to large databases using sophisticated methods

· provides context to search terms

· supports interoperability between information systems

· enables multilingual access to collections

· language independent notations can be linked to search terms of various verbal  languages

· it is possible to search in more than one language at the same time

· other languages can join later without the need to classify the resources again

· could serve as reference or switching language which enables

· convertibility between information languages

· the same level of specificity in all participating languages

· language independent coding

UDC classification

UDC classification represents a universal synthetic, faceted classification which can be adopted and used as an interactive information organizing and retrieval tool. UDC classification is mostly based on numerical notations, it uses language independent coding. The scheme is available in different languages and in machine readable form (UDC MRF). It is flexible more than other universal classification schemes; it supports very detailed expressions of complex subjects using a variety of common and special auxiliaries, specific symbols and punctuation.

Many internet services found out that the structure of UDC is too complicated to be used above all in online environment where the enumerative principle is predominating.

UDC classification system can be applied

· as an enumerative classification system (like DDC). All UDC numbers – single and complex (pre-combined) are treated as single UDC numbers (set of characters without meaning)

· as a synthetic (structured) classification system in which each component of complex number should be treated as a separate (meaningful) element entered in special position (e.g. subfields)

In our case, UDC classification system is used as an enumerative system: enumerative approach is more convenient in online environment; mapping process between verbal controlled terms and UDC notations (subject authority file) and mappings between UDC and DDC (subject categorization) requires enumerative taxonomy as well.

Semantic interoperability, cross-browsing and cross-searching

It is broadly accepted that the most important aspect of integrating traditional subject access tool in retrieval process is to support cross-browsing and cross-searching feature

Cross-browsing and cross-searching approach which is a vital task for users’ community, above all for non-English, non-French, non-German speaking people, supposes semantic interoperability among retrieval systems used in current heterogeneous online environment.

Semantic interoperability can be achieved trough different procedures; the most important seems to be the mapping process which consists in establishing

· links between verbal controlled terms and classification systems, e.g. UDC notations - method applied in the process of creating Subject authority file

· equivalents between verbal terms of different natural languages via switching language (e.g. UDC classification) – method applied in the process of creating Multilingual controlled vocabulary

· relationships between different classification systems via concordance tables (e.g. UDC-DDC classification – method applied in the process of creating scheme for Subject categorization of heterogeneous information resources using Conspectus method (UDC-DDC: experimental project, currently determined for internal use only)

The mapping process is being done intellectually

CZENAS - Czech National Subject Authority File

Subject authority file of CNL is an integrated indexing and retrieval tool in which verbal (controlled) terms are being linked to the UDC equivalent notations. When creating the subject authority file we respect IFLA recommendations

· to formulate Guidelines for subject authority records and for their interrelationships within subject authority files

· to consider possible relationships between subject authority records and classification

National subject authority file consists of four specific authority files

· Geographic authority file

· Chronological authority file

· Genre/form authority file (Formal descriptors)

· Topical authority file

Topical authority file

Topical authority file is a controlled vocabulary in which following kinds of relationships between terms are defined: equivalence (expressed: USE), hierarchical (expressed: BT-Broader term; NT-Narrower term) and associative (expressed: RT-Related term)

Equivalent relationship is identified between preferred terms and its variants (synonymous, variant spelling forms, alternative forms, opposite terms, specific narrower terms)

Hierarchical relationships can be established between valid (preferred) controlled terms, which form part of the same semantic domain and are connected by reciprocal NT, BT references

Associative relationship can be identified between terms which are related other than hierarchically, relationship is reciprocal.

Example

Mapping between indexing terms, UDC numbers and English equivalents

Controlled vocabulary structure is tied to a classification scheme so that relationships between indexing terms can be expressed more definitely.

Mapping process between Czech verbal expression and UDC numbers is being done intellectually. Candidates of controlled terms are chosen with document in hand (from bottom up) in order to suggest terms as specific as needed (not as specific as possible). Single or complex UDC numbers (pre-combined) are linked, English equivalents of preferred terms, mostly LCSH terms are chosen. Sometimes, we are not successful in finding LCSH equivalents since the LC terms are too broad: in this case, the reference sources like LC titles and subtitles file, www pages, full text databases, language vocabularies, encyclopaedias, different manuals are consulted. The proposals of preferred terms linked to the UDC class numbers and English equivalents are sent to a special senior cataloguers working group for approval, approved authority records are via special programme procedure entered into the authority database.

Subject authority file can be browsed by controlled terms, English equivalents, UDC notations, geographic names, formal descriptors, and chronological terms (planned).

The authority file is searchable by subject terms only at present. (In future, our intention is to make it searchable by UDC class numbers as well, using first element of notation and right truncation).

Subject categorization of heterogeneous information resources using Conspectus method

Conspectus is a systematic, subject-organized survey of the collections to provide a baseline for future management decision.

The Conspectus method of collection assessment can provide the accurate, systematic data that libraries need for: collection planning, acquisitions budget development and support, accreditation, fund-raising, grant applications, cooperative collection development, other collection management applications.

Subject scheme is hierarchically organized:

The 24 subject divisions are subdivided by approximately 500 subject categories, which are further subdivided by approximately 4,000 descriptors. Each of the subject divisions, categories and descriptors directly relates to a range of classification numbers.

The Conspectus was developed for use in libraries organized either using the Library of Congress (LC) classification or the Dewey Decimal Classification (DDC) structures. The Universal Decimal Classification (UDC) differs sufficiently to require the use of additional tables and adaptations to ensure compatible and comparative results. Each of the organizing systems for libraries has characteristics that reflect the worldview of knowledge and literature as well as value systems from a particular point in time and place.

The adaptation of the Conspectus structure to accommodate the local practice of the Czech National Library was one of the first issues to be addressed. While the Conspectus divisions with their categories and more detailed subjects provide some assistance with UDC classification and terminology, additional work in identifying comparable and/or different classification usage was required. The concordance with both DDC and UDC classification numbers, the corresponding subject terminology in both English and Czech provides a needed clarification of the subject structure to be used in writing policy based on the IFLA standard, for implementing collecting strategies, and for navigating and linking resources within the UIG.

Marie Balíková