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…

Places the question of the relatively limited storage capacity of optical data disks when applied to very large databases into practical perspective, and considers some of the possibilities offered by the integration of different databases on a single CD-ROM. The advantages and disadvantages of three production options for integrated databases are…

Reports information gathered from eight vendors on the preparation of bibliographic data for CD-ROM public access catalogs: (1) sources of bibliographic records; (2) duplicate record handling; (3) holdings and location information; (4) maintaining the database; (5) authority control; (7) record corrections; (7) extraction of subsets; (8)…

Surveys some of the traditional and nontraditional electronic sources of information that can be of use in research and teaching. The discussion includes information about: 1) cost; 2) ease of use; 3) the earliest bibliographic entries; and 4) the frequency of updates. (Author/LMO)

Compares the available databases, retrieval techniques and costs of traditional online searching of remote databases and local online access, i.e., databases available at the point of use via CD-ROMs or site licenses. The options and risks of local online access, and the possible impact on the database industry, are discussed. (CLB)

Describes variations in current bibliographic databases in such areas as database organization, contents, authority control, and uses. The discussion covers the implications of these factors, optical disk technologies, and the Linked Systems Project for the future of national bibliographic databases. (nine references) (CLB)

Describes the unique reliability problems of very large databases that necessitate specialized techniques for hardware problem management. The discussion covers the use of controlled partial redundancy to improve reliability, issues in operating systems and database management systems design, and the impact of disk technology on very large…

This paper identifies the bibliographic and numeric databases on CD-ROM and computer diskette that should be most useful for investigators in communication, marketing, and communication education. Bibliographic databases are usually found in three formats: citations only, citations and abstracts, and full-text articles. Numeric databases are…

Presents an access method for temporal data called the Snapshot Index that reconstructs a past state of a time-evolving collection of objects. Previous approaches to temporal access methods are reviewed, and migrating data to write-once optical disks are discussed. (Author/LRW)

Profiles 25 database distribution and production companies, all of which responded to a 1997 survey with information on 54 separate online, Web-based, or CD-ROM systems. Highlights increased competition, distribution formats, Web versions versus local area networks, full-text delivery, and pricing policies. Tables present a sampling of customers…

Review of encyclopedias and other databases available on CD-ROM focuses on the International Encyclopedia of Education (IEE). Problems with software and hardware are described, perspectives from the computer industry are presented, the commercial potential of CD-ROMs is discussed, and a list of sources is provided. (six references) (LRW)

Discusses issues relating to recent introductions of CD-ROM technologies in libraries and considerations that have motivated libraries to choose networking CD-ROMs over the standalone approach. Factors discussed include cost effectiveness, the flexibility of the networking approach, and performance considerations. A glossary of terms is provided.…

Discusses the need for comprehensive and accurate sources of information for librarians looking for information about online databases or CD-ROMs and compares, examines, and makes recommendations regarding three print and electronic directories--the "Gale Directory of Databases," Bowker's "World Databases," and Waterlow New…

This digest reviews three CD-ROM (compact disc-read only memory) versions of the ERIC (Educational Resources Information Center) database currently being delivered or tested and provides information for comparison. However, no attempt is made to recommend any one product. The advantages and disadvantages of the acquisition of CD-ROM databases are…

This compendium of 44 articles written by leading authorities provides an in-depth and instructive overview of CD ROM (Compact Disk--Read Only Memory) for both the professional and the newcomer to the field. Three articles serve as an introduction to the book: (1) "As We May Think," Vannevar Bush; (2) "Finally It Works--Now It Must…