Describes an approximate document ranking process that uses a compact array of in-memory, low-precision approximations for document length. Combined with another rule for reducing the memory required by partial similarity accumulators, the approximation heuristic allows the ranking of large document collections using less than one byte of memory…

Examines how online versions of databases vary on different systems. Differences are grouped into three categories: obvious differences, including easily available information such as updating, dates covered, and price; database choice, including subfile structure, field structure, and content; and system choice, including support and system…

Proposes a new learning algorithm to improve the retrieval effectiveness of the search system used in the hypertext environment using an extended Boolean model with links to improve the ranking of retrieved items. Highlights include the basic retrieval scheme, the learning scheme, and a review of basic probabilistic retrieval models. (Contains 32…

Examines novel computer filing systems which have particular application to office information storage and retrieval requirements. A variety of filing systems and their major characteristics are reviewed, ranging from network-based file servers to digital image storage and retrieval systems. Desirable characteristics of a modern electronic office…

Provides an overview of methods for improving the effectiveness of Boolean retrieval systems, including document clustering, relevance feedback, weighted term searching, ranked output, and fuzzy set theory. The discussion of experimental studies with the SMART and SIRE systems focuses on the implementation and results of these methods. (69…

The first of three articles reports the effectiveness of a feature-matching approach to computer retrieval of graphic information. The second discusses the use of multivariate techniques to measure perceived complexity of database searching by users. The third explores the limitations of user consultation in database design. (Author/CLB)

Presents a study of journal title elements as represented in eight databases, and describes four measures developed to show the extent of standardization within a database and some of its implications for searching. (FM)

Examines the relative benefits and searching philosophies of five major search systems (DIALOG, ORBIT, BRS, NLM, and DOE/RECON) as a selection aid. Differences in command language, full text searching capability, use and expression of Boolean operators, and searching mechanisms are discussed, and comparison charts and system/database comparisons…

Describes fast, dynamic update algorithms for document retrieval systems. B-trees are discussed; the M-B-T file directory structure is explained; insertions and deletions in inverted files are described; and performance evaluation is discussed. An appendix provides the formal definition of an M-B-T directory. (Contains 18 references.) (LRW)

This article reports results of a case study of text-based online and CD-ROM databases that identified design characteristics that are important to high school students' use for higher-level learning as well as for information access and retrieval. Implications for the design of databases are suggested. (Contains 62 references.) (LRW)

Describes the broad scope of publications and information content in both printed and computer-readable versions of Chemical Abstracts Service Source Index (CASSI), including special characteristics, growth rates, and the use of CASSI as a union list. A discussion of the uses of CASSI which are possible through searching the computer-readable file…

Presents survey of two groups of databases covering patent literature: patent literature only and general literature that includes patents relevant to subject area of database. Description of databases and comparison tables for patent and general databases (cost, country coverage, years covered, update frequency, file size, and searchable data…

Describes the methodology and results of a study comparing the overlap of Enviroline, Pollution, and the Environmental Periodicals Bibliography files through searches on acid rain, asbestos and water, diesel, glass recycling, Lake Erie, Concorde, reverse osmosis wastewater treatment cost, and Calspan. Nine tables are provided. (RBF)

Reports the findings of a study which examined the question of submitting error reports to OCLC for the purpose of database quality control, and describes ENHANCE, a program that would provide online error correction capability for member libraries. Eight references are cited. (FM)

Discussion of image database systems focuses on semantic queries and shows how an image is abstracted into a hierarchy of entity names and features; how relations are established between entities visible in the image; and how a "fuzzy" matching technique is used to compare semantic queries to image abstractions. (Author/LRW)