Describes a genetic algorithm (GA) that assigns weights to query terms in a ranked-output document retrieval system. Experiments showed the GA often found weights slightly superior to those produced by deterministic weighting (F4). Many times, however, the two methods gave the same results and sometimes the F4 results were superior, indicating…

This evaluation of the DIALOG Medical Connection, a new user-friendly system that provides access to several online health sciences databases, describes searching, changing databases, documentation, online help, access, costs, and training, and compares the features of this system with those of other systems that are currently available. Three…

The last installment in a three part series compares commands and features for accessing and manipulating the results obtained from the DIALOG and QUESTEL information systems. Highlights include enhancements to syntax and defaults, options for output arrangement and retrieval, reformatting of selected data, memory, unique features, and examples.…

This second of a three-part series compares search features (i.e., truncation symbols, boolean operators, proximity operators, phrase searching, save searches) of two databases providing legal information. Search tips concerning charges and effective searching and tables listing functions of commands and proximity operators for both databases are…

Examines range of coverage and principles of inclusion of dissertations in PsycINFO by comparing searches done on PsycINFO and Dissertation Abstracts Online. Searchers are advised to be skeptical about the accuracy and completeness of vendor documentation and the practical journal literature. Search strategies used are appended. (eight references)…

Describes a study that compared two electronic document delivery systems, Faxon Finder and UnCover2, by searching seven subjects in various disciplines and checking journal overlap and article overlap. Results show a lack of overlap, suggesting that both systems cover different ground and that a standard database system has yet to be found.…

Identifies and describes online databases containing references to materials on artificial intelligence, robotics, and expert systems, and compares them in terms of scope and usage. Recommendations for conducting online searches on artificial intelligence and related fields are offered. (CLB)

Aspects of Data Fusion (DF) for information retrieval are explored. Based on a geometrical model of DF, it is shown that in the ideal case, performance of DF for a pair of information retrieval schemes may be approximated by a quadratic polynomial. Compares counter-intuitive cases of DF with cases that behave according to the geometric model. (AEF)

Two tables compare projected costs of online versus offline retrieval of citations from 50 databases using BRS and DIALOG. Data include database; databank; cost of access per hour; cost of 15-minute search with no retrieval; and cost of 15-minute search plus cost of 10 and 30 online or offline citations. (CLB)

Reports on comparison of costs of manual versus computer reference service at Deerfield Public Library (Illinois) and Houston Public Library. Costs for online services, equipment, searches per database, salaries, reference books, business reference subscriptions, periodicals, and labor are included. Unknown costs and time involved to answer…

Second article in a three-part series focuses on enhancements of search commands and features in the DIALOG and QUESTEL information systems. Highlights include system responses and capacities (aids to searching); search commands and features (proximity searching, field specification, limits); concatenating complex requests; and saving search…

Considers the quality of bibliographic control achieved by the three online databases offering significant coverage of the literature of librarianship: ERIC, LISA, and Library Literature. Focusing on coverage and indexing, the study compares online search results with the tables of contents of 67 journals and reports the results. (27 references)…

Describes the availability of databases held on DIALOG, ESA-IRS, and DATA-STAR. Database overlap among the systems, prices, database contents, and data transmission costs are addressed; and results of a search of the ENVIROLINE database on each system are presented. The appendix lists subjects referenced on each system and compares database…

This comparison of three menu systems for end-users considers user-friendliness, cost, databases offered, hours of availability, and search options. The differences are shown to indicate that they are intended for users with different amounts of knowledge and training. The conclusion reached is that each system is unique. (five references) (EAM)

Explains the use of proximity operators as a search technique in online searching, especially in large full-text databases. Differences in proximity operators on various online systems are discussed and future possibilities are considered. (LRW)