Stephen S. Hearn

Machine-Assisted Validation of LC Subject Headings: Implications for Authority File Structure

SUMMARY Many kinds of structure can be discerned in the headings and rules governing the Library of Congress Subject Headings. By addressing these structures at different levels, librarians can develop different approaches to the machine-assisted validation of subject headings, from the checking of individual words to the validation of complex forms of heading/subdivision compatibility. Using computer programs to assist with maintenance of subject headings is becoming increasingly necessary as technical services librarians strive to create consistent and useful patterns of subject collocation in library catalogs.

A Review of “International Standard ISO 25964-2: Information and Documentation—Thesauri and Interoperability With Other Vocabularies—Part 2: Interoperability With Other Vocabularies”

The document under review is the second part of ISO 25964, Information and Documentation—Thesauri and Interoperability with Other Vocabularies, following the 2011 publication of Part 1: Thesauri for Information Retrieval. It was prepared by Technical Committee ISO/TC 46, Information and Documentation, Subcommittee SC 9, Identification and Description. Where Part 1 included content revising earlier standards ISO 2728:1986 and ISO 5964:1985, Part 2 covers new ground in focusing on interoperability across controlled vocabularies. Clauses (sections) 1–16 lay the groundwork for discussing interoperability, and Clauses 17–24 provide guidelines for mapping particular types of controlled vocabularies and classification schemes to other systems. This review will describe the foundational Clauses 1–16 in some detail, briefly summarize Clauses 17–24, and conclude with comments about the light shed by the standard on the prospects for interoperability mapping. Clause 1, Scope, is brief enough to quote in its entirety:

Introduction: Bibliographic database quality

Database quality is a simple expression for a complex, multifaceted concept. Attempts to analyze and measure database quality in library catalogs quickly come up against this complexity. Is quality a question of being error-free, or of completeness, or of currency? Is it measured by the word, or by the field, or by the record, or by the index, or for the catalog as a whole? How do issues of system functionality and performance factor into measures of database quality? Can one demonstrate a clear connection between database quality however defined and the catalog’s usefulness for its end users? Given that the standards for catalog data are in a constant state of flux, with new rules and new heading forms and new conventions replacing old ones, is maintaining a high quality database even a realistic goal? What should the goal be? The authors contributing articles to this special issue of Cataloging & Classification Quarterly offer diverse perspectives on the question of what database quality is and should be. Janet Swan Hill looks back over the last half century and offers an account of how discussions of database quality have progressed from an insular illusion that the each library could fully control and possibly “perfect” its catalog, through a time when Library of Congress records and leadership promised a “gold standard” for quality, to a recognition that library data must prove its usefulness in an environment where the catalog draws from and is only one among many data sources. As com-