Rethinking Subject Cataloging in the Online Environment.

Rethinking Subject Cataloging in the Online Environment New search capabilities in online catalogs have numerous implications for (1) the use of subject cataloging in existing records, (2) the design of thesauri, and (3) the design of the online catalog user-system interface. Online search capabilities are themselves seen as a form of indexing, and it is argued that access is determined by the total mix of preexisting and added "search capability" indexing. The design of a "superthesaurus" as part of a friendly front-end user interface is described. Said thesaurus is geared to the needs of users rather than indexers and incorporates the findings of recent research on the patterns of subject description by searchers. Its design also reflects the different demands of online searching as opposed to manual searching. The introduction of online catalogs into libraries opens up impressive new possibilities of retrieval power and ease of use for ourselves and our clients. [1,2] Our task now is to design the intellectual content and arrangement of catalogs so as to take maximum advantage of these new technical capabilities. In order to do that, we need to understand the interaction between the database--the bibliographic records--and the search capabilities of the online system. There are many ramifications, some obvious and others quite subtle, of this interaction. This article develops these ramifications in three areas relating to subject cataloging: * role of present subject cataloging in existing records * subject headings/thesaurus design * system-user interface design Throughout the discussion, emphasis will be on improving user access and retrieval effectiveness. PRESENT ROLE OF SUBJECT CATALOGING A note on terminology: Throughout this article, the terms indexing and subject cataloging are used interchangeably. Similarly, thesaurus is used to refer both to Library of Congress Subject Headings (more precisely called a subject heading list), as well as to other term lists more conventionally referred to as thesauri. The distinctions between subject cataloging and indexing as processes and between subject heading lists and thesauri are important more for historical reasons than for present practice. Though differences may still be discerned, so many changes in thinking about them are necessitated by the new circumstances associated with the online environment that traditional distinctions are largely meaningless. Based on our experience with card catalogs, we have been conditioned to think of the subject indexing in a catalog as consisting of subject headings and classification numbers. When a card catalog is put online it is natural, then, to continue this assumption--to think of the indexing in an online catalog as consisting of the subject elements already present in the database before it was automated. We think of an online catalog as simply the same catalog we had before, but now online-accessible. But, in fact, online search capabilities themselves constitute a form of indexing. Subject access to online catalogs is thus a combination of original indexing and what we might call "search capabilities indexing" (more on this presently). The interactions between these two kinds of indexing can be subtle. A range of search capabilities is superimposed on textual materials of various kinds in the bibliographic record, including natural and controlled languages. The resulting interaction has a variety of effects on the quality of searches done by users of online catalogs. The effects are not only additive. Sometimes they cancel each other out or are so synergistic as to be multiplicative. Typical online search capabilities are keyword searching, Boolean searching, truncation, and multi-index searching (that is, combining query terms from more than one index, e. …