Describes a computerized information retrieval system that uses three agglomerative hierarchic clustering algorithms--single link, complete link, and group average link--and explains their implementations. It is noted that these implementations have been used to cluster a collection of 12,000 documents. (LRW)

Describes an approach that combines concepts from information retrieval, fuzzy set theory, and genetic programing to improve weighted Boolean query formulation via relevance feedback. Highlights include background on information retrieval systems; genetic algorithms; subproblem formulation; and preliminary results based on a testbed. (Contains 12…

Presents an algorithm for use in online information retrieval which will generate a list of bibliographic citations derived from a preselected relevant document and which measures the relatedness of retrieved items to the preselected document. A test of the algorithm in retrieving medical literature is described. Two figures are included. (JL)

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…

As the use of online literature searching systems increases, the need for reducing the amount of nonrelevant material encountered by the users becomes more apparent. One method for achieving greater selectivity in document retrieval is by using relevance (or utility) estimates from past users to estimate document values for future users. However,…

Discussion of a new method of index term dictionary compression in an inverted-file-oriented database highlights a technique of word coding, which generates short fixed-length codes obtained from the index terms themselves by analysis of monogram and bigram statistical distributions. Substantial savings in communication channel utilization are…

The Hepatitis Knowledge Base (text of prototype information system) was used for modifying and testing "A Navigator of Natural Language Organized (Textual) Data" (ANNOD), a retrieval system which combines probabilistic, linguistic, and empirical means to rank individual paragraphs of full text for similarity to natural language queries…

Discusses ranking techniques for document retrieval and proposes an evaluation, or filtering, technique that reduces costs and memory usage by early recognition of which documents are likely to be highly ranked. Highlights include index design, ranked query evaluation, reducing the number of accumulators, inverted file structures, and experimental…

Analytical methods for facilitating comparison of multiple sets during online searching are illustrated by description of specific searching methods that eliminate duplicate citations and a factoring procedure based on syntactic relationships that establishes ranked sets. Searches executed in National Center for Mental Health database on…

Presents a dynamic model of user behavior when scanning an information storage and retrieval system output list, compares rules for determining the user's optimum stopping point, presents an algorithm for implementing the Bayesian model, and discusses implications for retrieval system design. Provided are 13 figures and 15 references. (Author/RBF)

Explores potential of mathematical theory of communication for information science and examines question of how to encode a message at time it is encountered for subsequent recall. Examples of problem, a prototype computer program and experiment, coding as embedding in associational nets, and nature of information are discussed. (Nine references.)…

Describes preliminary investigation of the use of International Computers Limited's Distributed Array Processor (DAP) for parallel searching of large serial files of documents. DAP hardware and software, test collections, measurement of DAP performance, search algorithms, experimental results, and DAP suitability for interactive searching are…

Presents methods of information query building in selective dissemination of information systems based on user's publications and examines possible compatibility between user's information queries and his publications. Methods of information query construction determined by logical operators AND, OR, NOT and set of weighted keywords are described.…

The goal of this project was to find ways of enhancing the efficiency of searching machine readable data bases. Ways are sought to transfer to the computer some of the tasks that are normally performed by the user, i.e., to further automate information retrieval. Four experiments were conducted to test the feasibility of a sequential processing…

Describes a genetic algorithm (GA) that assigns weights to query terms in a ranked-output document retrieval system. Experiments showed the GA often found weights slightly superior to those produced by deterministic weighting (F4). Many times, however, the two methods gave the same results and sometimes the F4 results were superior, indicating…