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)

Describes a method for advance estimation of user charges for queries in relational data model-based numeric databases when charges are based on data retrieved. Use of this approach is demonstrated by sample queries to an imaginary marketing database. The principles and methods of this approach and its relevance are discussed. (MBR)