Indexing consistency in MEDLINE

The quality of indexing of periodicals in a bibliographic data base cannot be measured directly, as there is no one "correct" way to index an item. However, consistency can be used to measure the reliability of indexing. To measure consistency in MEDLINE, 760 twice-indexed articles from 42 periodical issues were identified in the data base, and their indexing compared. Consistency, expressed as a percentage, was measured using Hooper's equation. Overall, checktags had the highest consistency. Medical Subject Headings (MeSH) and subheadings were applied more consistently to central concepts than to peripheral points. When subheadings were added to a main heading, consistency was lowered. "Floating" subheadings were more consistent than were attached subheadings. Indexing consistency was not affected by journal indexing priority, language, or length of the article. Terms from MeSH Tree Structure categories A, B, and D appeared more often than expected in the high-consistency articles; whereas terms from categories E, F, H, and N appeared more often than expected in the low-consistency articles. MEDLINE, with its excellent controlled vocabulary, exemplary quality control, and highly trained indexers, probably represents the state of the art in manually indexed data bases.     

Program Evaluation in Libraries: Relating Operations and Clients

Evaluators of library programs have different perspectives on why to conduct an evaluation and also how to do so. The author suggests that a minimal approach to conducting a library program evaluation is to prove that the program exists. But this perspective has expanded to include different degrees of interest in the client and operations, culminating in a combined focus that leads evaluators to conduct outcome assessments. The chapter includes speculation on what motivates managers to undertake an evaluation, a review of some ways that library evaluations are conducted, and a discussion of several examples of program evaluations. Though there are not single directives for undertaking a library program evaluation, there are a variety of tools and advice to entice librarians to do more of them as a way to improve understanding the value of a library to its clientele and in society.