An operational, comprehensive, economical method for updating and correcting entries in a computerized bibliographic system is presented. The technique was developed in connection with the East African Agricultural Bibliographic Project at West Virginia University. Data modification operations are discussed as well as the limitations of the method…

A model which relates the access control and indexing functions. The model is based on concept protection which allows a practically unbounded number of levels (subsets) of protection without requiring a fixed hierarchy among the levels. This protection is offered independently for each of the user operations allowed. (Author)

Discusses the developments that have positively or adversely affected abstracting and indexing services over the past several decades, addressing such topics as the impact of computers and the migration from print-on-paper to online information provision. Forecasts for the near and long-term future are made and a reference list is included. (JL)