Introduces the multicharacter trie as an index structure that can improve the time needed for retrieving full-text materials stored on CD-ROMs. The advantages of this structure compared to other structures are described, and experimental results comparing it to the widely used B+ tree and other structures used for full-text retrieval are…

Explores the new storage technology of optical data disks and introduces a data structure, the inverted signature tree, for storing data on optical data disks for efficient text searching. The inverted signature tree approach is compared to the use of text signatures and the B+ tree. (22 references) (Author/CLB)

Presents three text compression methods of increasing power and evaluates each based on the trade-off between compression gain and processing time. The advantages of using hash coding for speed and optimal arithmetic coding to successor information for compression gain are discussed. (26 references) (Author/CLB)

Reports a study that examined 10 collections of mainly scientific subject areas indexed using Farradane's system of relational indexing. It compared (1) the use of relations, (2) the use of concept types, (3) the cross sections (or shape) of abstracts, and (4) the properties of "nodes." Statistical tables and graphs are included.…

Describes a study comparing information retrieval from print and CD-ROM versions of Compton's Encyclopedia. Forty-eight sixth-grade students searched four questions in both versions. The results showed that the searches took the same amount of time in both. The novice searchers were able to use an information retrieval system with minimal…

Discusses properties of multiple attribute tree (MAT) and inverted file structures; establishes suitability of MAT data structure for bibliographic files using worst-case performance measures; provides arguments to establish MAT average case superiority; and proposes an efficient adaptation of MAT data structure to exploit special features of MAT…

Discusses the PRECALL, PRR (probability of relevance given retrieval), and EP (expected precision) approaches for dealing with the problem of weak ordering in information retrieval systems. Findings of two experiments comparing evaluation results obtained by PRR and EP are reported. Several mathematical formulas and proofs are included. (20…

Compares two methods of information retrieval--one that rates documents according to a query and another that uses relevant documents to find further relevant documents (i.e., neighboring documents). Highlights include experiments at the National Library of Medicine; feedback; vector cosine retrieval; and a measure of retrieval effectiveness…

Explains an experiment in text-searching retrieval for cancer questions which developed and used computer procedures (via human simulation) to select search words from medical dictionaries. This study is based on an earlier one in which search words were humanly selected, and the recall results of the two studies are compared. (Author/LRW)

Describes a study which focused on the application of magnitude estimation, an open-ended scaling technique developed in the field of sensory psychophysics, to the task of measuring relevance judgments. The discussion covers potential biases found in magnitude estimation and in commonly used category rating scaling processes. (23 references)…

Describes the two basic approaches to the calculation of term discrimination values for automatic indexing. The results of an experiment that investigated the differences between algorithms of these two approaches in terms of their impact on the discrimination value model are reported and discussed. (13 references) (Author/CLB)

Describes experiments that compared a new method for automatically analyzing semantic structures in text by statistical means with the standard vector space model. Findings indicate that combining both methods improved performance over either alone. The effects of other experimental variables on retrieval performance (term weighting, suffix…

Discussion of informetric distributions shows that generalized Leimkuhler functions give proper fits to a large variety of Bradford curves, including those exhibiting a Groos droop or a rising tail. The Kolmogorov-Smirnov test is used to test goodness of fit, and least-square fits are compared with Egghe's method. (Contains 53 references.) (LRW)

Describes an investigation of the use of document components, such as terms, sentences, and whole documents, for indexing and retrieval. A number of probabilistic similarity measures based on document components are studied, as well as a new method of handling probability estimations involving small sample sizes. (24 references) (Author/CLB)

Demonstrates efficiency of preparation of query description using semantic analyser method based on analysis of semantic structure of documents in field of automatic indexing. Results obtained are compared with automatic indexing results performed by traditional methods and results of indexing done by human indexers. Sample terms and codes are…