Describes the theoretical framework of a retrieval system that uses data structures called bitmaps to improve search algorithms for medium-sized systems. Information retrieval systems that contain the full text of the documents are discussed, and the use of inverted files such as concordances for small texts is explained. (24 references) (LRW)

Following a discussion of derivative versus assignment indexing, use of roles, and concept behind Preserved Concept Indexing System, features of PERMDEX (microcomputer program to assist in creation of permuted printed index) are described including indexer input and prompts, the shunting algorithm, and sorting and printing routines. Fourteen…

Presents uniform and efficient approach for processing all truncated query terms in information retrieval which requires one disk access to obtain from the permuted dictionary all strings represented by truncated term. The problem of the overhead storage required to implement the permuted dictionary is discussed. Fifteen references are provided.…

Analyzes the formal properties, structural consequences, similarities, and differences of link indicators, brackets, and cohesion separators in the query languages employed in information retrieval. Eleven figures, a 32-item reference list, and appendices on Extended Backus Notation and the formal definition of the Formal Relevance Language are…

Describes an indexing technique based on overlapping word fragments as reference strings that are linked in a directed graph structure which makes possible exact match-, partial match-, and masked-partial match-retrieval and indicates search strategies for each case. Eight figures, two tables, and nine references are provided. (RBF)

Discusses the problems of compressing a large textual database for storage on CD-ROM. A text-compression algorithm is presented, new algorithms for compression of indices are described, and the ARTFL (American and French Research on the Treasury of the French Language) database is used as an example. (14 references) (LRW)

Proposes a single underlying structure for the production of a variety of computer index displays, using a networking system which represents both concepts and links by nodes. Desirable characteristics of index displays are outlined, and algorithmic extraction of subnetworks for local use is discussed. References are included. (Author/BK)

Examines through a series of mathematical models (theorems, descriptions, and examples), properties and operations on inverted files, which are used in an information retrieval system based on thesaurus with weighted descriptors. (CWM)