Although the topological index does not uniquely correspond to the individual structure of a graph, it roughly represents the topological nature of the graph. Examples are given for using the topological index as a first sorting device for coding and retrieving structures, especially of fused polycyclic systems. (14 references) (Author/NH)

The compatibility property of documentation system is defined by the capacity of the system to posit relationships of equivalence. This state is reached when cataloging references are properly structured and when a program allows searching the same data in the system. (15 references) (Author/MM)

The MARC system provides the medium through which the cataloging record is converted to machine-readable form. (Author)

A brief article on periodicals issued by companies and other organizations which are available to libraries on a complimentary basis. (MM)

Summarizes the characteristics of TOXIN, CHEMFILE, and the Product Profile Information System (PPIS), nonbibliographic databases used by Shell Oil Company's Health, Safety, and Environment Organization. (FM)

Describes the STATUS information retrieval system, which is a free text, Boolean-type system, concentrating on recent developments and improvements. The use of pre- and postprocessors is discussed, and how STATUS can be integrated into existing information systems is illustrated. An appendix lists selected users and applications. (Author/JD)

Reexamines the utility of edge-notched cards as an inexpensive alternative to computers for indexing small specialized collections. Five references are listed. (RAA)

Introduces this special issue on the theory and foundations of information retrieval by discussing the growth of non-library items, the issues of speed and precision in automated retrieval, the differences between document and data retrieval, the scope and foundations of information retrieval, and the future of the field. (JD)

Discusses the use of inverted files in information retrieval systems and proposes a document identifier reassignment method to reduce the average gap values in an inverted file. Highlights include the d-gap technique; document similarity; heuristic algorithms; file compression; and performance evaluation from a simulation environment. (LRW)

Describes the application of semiotic concepts and tools to information-retrieval systems design, which is viewed as a social practice in which the main disjunction is between the two conflicting acts of detonation and prescription. These two conflicting language games are discussed within the framework of the Okapi information retrieval system.…

Presents a general method to construct ordered similarity measures in information retrieval based on classical similarity measures for ordinary sets. Describes a test of some of these measures in an information retrieval system that extracted ranked document sets and discuses the practical usability of the ordered similarity measures. (Author/LRW)

Describes the Constituent Object Parser (COP), a domain independent syntactic parser developed for use in information retrieval and similar applications. The syntactic structure of natural language entities is discussed, and the mechanisms by which COP handles the problems of conjunctions, ellipsis, and discontinuous constituents are explained.…