Discusses the problems associated with using connect time as the basis of user fees for searching numeric online databases, and proposes a methodology for user charge estimation based on query formulation and results. (87 references) (CLB)

Provides an overview of the development and use of numeric databases, and of the evolution of user charging methods for all online information retrieval systems. The need to provide database users with advance estimates of charges is discussed, and a methodology for charge estimation is presented. (87 references) (CLB)

Discussion of user interfaces to information retrieval systems focuses on interfaces that incorporate thesauri as part of their searching and browsing facilities. Discusses research literature related to information searching behavior, information retrieval interface evaluation, search term selection, and query expansion; and compares thesaurus…