Examines factors that determine user charges based on query processing costs in numeric databases, and analyzes the problem of estimating such charges in advance. An approach to query cost estimation is presented which is based on the relational data model and the query optimization, cardinality estimation, and file design techniques developed in…

After reviewing the literature on automatic indexing research an experiment is described which examined term distribution and the effectiveness of the Two Poisson and Three Poisson Models in identifying good index terms. The conclusion reached is that these models should be applied with caution in document retrieval. (25 references) (EAM)

Presents an online search strategy to help find pairs of medical literatures that are logically related but non-interactive, meaning the two pairs have no articles in common, do not cite each other, and are not co-cited. Each stage of the search strategy is described and favorable results are discussed. (four references) (CLB)

Describes a citation analysis that examined the 28 best articles published from 1969-1996 in JASIS ("Journal of the American Society for Information Science")(ASIS 1999 Handbook and Directory, p.25). Results highlight single-authored works that are twice as long (16.21 pages) as the average article (8.93 pages), are cited and self-cited…

Briefly reviews early work in documentation and text processing, and predictions that were made about the creative role of computers in information retrieval. An attempt is made to explain why these predictions were not fulfilled and conclusions are drawn regarding the limits of computer power in text retrieval applications. (Author/CLB)

The issue of free-text versus controlled vocabulary is examined. The history of the issue, which is seen as beginning with the debate over title term indexing in the nineteenth century, is reviewed and questions not satisfactorily addressed by previous research are raised. (Author/EM)

Describes the history, scope, and applications of the Chemical Abstracts Service Chemical Registry System, a computerized database that uniquely identifies chemical substances on the basis of their molecular structures. Explains searching the system is and discusses its use as an international resource. (66 references) (Author/LRW)

Develops a method of rough retrieval, an application of the rough set theory to information retrieval. The aim is to: (1) show that rough sets are naturally applied to information retrieval in which categorized information structure is used; and (2) show that a fuzzy retrieval scheme is induced from the rough retrieval. (AEF)

Discussion of index construction for large text collections highlights a new indexing algorithm designed to create large compressed inverted indexes "in situ." Topics include a computational model, inversion, index compression, merging, experimental test results, effect on retrieval performance, memory restrictions, and dynamic…

Investigates performance of online searchers using a prototype expert system that automatically reformulates queries to improve results and ranks retrieved passages to speed identification of relevant information. Results indicated that the system significantly reduced the number of queries needed, produced marginally significant improvements in…

Describes methods for applying natural-language processing for automatic concept-based indexing of full text and methods for exploiting the structure and hierarchy of full-text documents to a large collection of full-text documents drawn from the Health Services/Technology Assessment Text database at the National Library of Medicine. Examines how…

Discusses how imprecision and uncertainty are dealt with in the UFO (Uncertainty and Fuzziness in an Object-oriented) database model. Such information is expressed by means of possibility distributions, and modeled by means of the proposed concept of "role objects." The role objects model uncertain, tentative information about objects,…

Designed to measure end-users' efficacy in online searching based on their presearch experience with printed literature retrieval systems for the search topic, this experiment examined differences between manual searches preceding electronic searches and vice versa. The results were not statistically significant due to the small sample size.…

Reports the results of a qualitative analysis of cocited author retrieval performance. The discussion covers the effects on recall of first author only access and the ability of cocited author search techniques to enhance retrieval performance. Multiple author frequency data is also presented. (14 references) (CLB)

Investigates information retrieval from hypertext on the World Wide Web. Significant main and interaction effects were found for both link density (number of links per display) and display format (paragraphs or lists) on search performance. Low link densities displayed in list format produced the best overall results. Expert browsers performed…