Presents a formal model for specification of logical requirements of computer-based information systems that incorporates structural and dynamic aspects based on two separate models: the Logical Information Processing Structure and the Logical Information Processing Network. The model's role in systems development is discussed. (MBR)

Presents a relational logical model to support a sophisticated document retrieval system in which flexible forms of inferential and associative searching can be performed, and provides examples of ad hoc inquiries. Several problems of particular importance to document retrieval are discussed in terms of this model. (27 references) (Author/CLB)

Presents a four-stage hypothesis of information systems development based on computational capability, storage capability, communications capability, and effective voice input. Moore's Law and Mooers' Law are explained, the interface between the system and the user is discussed, and projections for the future are suggested. (21 references)…