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)

Describes the design of a stemming algorithm for searching Latin text databases. The algorithm uses a longest-match approach with some recoding but differs from most stemmers in its use of two separate suffix dictionaries for processing query and database words that enables users to pursue specific searches for single grammatical forms of words.…

Describes SWEAR (Systematic Weighting and Ranking), a powers-of-two algorithm that can be used for searching the World Wide Web or any large database that automatically creates discrete, well-defined result sets and displays them in decreasing order of likely relevance. Also discusses fuzzy sets. (Author/LRW)

Discusses end-user searching in Boolean information retrieval systems considers the role of search intermediaries and proposes a model of user preferences that incorporates a user's profile. Highlights include document representation; information queries; document output ranking; calculating user profiles; and selecting documents for a local…

This study of ranking algorithms used in a Boolean environment is based on an evaluation of factors affecting document ranking by information retrieval systems. The algorithms were decomposed into term weighting schemes and similarity measures, representatively selected from those known to exist in information retrieval environments, before being…

Words and word fragments from the computer-readable data bases "Chemical Abstracts Condensates" and "Biological Abstracts Previews" were analyzed in terms of length, number, and frequency of appearance to determine some parameters upon which inversion of these data bases could be predicated. Types (unique words or fragments)…

Discusses indexes for text databases and presents an efficient implementation of an index for text searching called PAT array, or suffix array, where the database is stored on secondary storage devices such as magnetic or optical disks. Additional hierarchical index structures and searching algorithms are proposed that improve searching time, and…

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…

Describes a project at the University of Sheffield that is investigating the use of nearest-neighbor retrieval algorithms for full-text searching. Nearest-neighbor searching is compared with Boolean retrieval and hypertext, and an experimental text retrieval system called INSTRUCT (Interactive System for Teaching Retrieval Using Computational…

Presents a probabilistic technique to retrieve passages from texts having a large size or heterogeneous semantic content. Results of experiments comparing the probabilistic technique to one based on a text segmentation algorithm revealed that the passage size affects passage retrieval performance; text organization and query generality may have an…

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…

Describes a two-phase stemming algorithm which consists of word root identification and automatic selection of word variants starting with same word root from inverted file. Use of algorithm in book catalog file is discussed. Ten references and example of subject search are appended. (EJS)

Discusses the results of modeling the performance of searching large text databases via various parallel hardware architectures and search algorithms. The performance under load and the cost of each configuration are compared, and a common search workload used in the modeling is described. (Contains 26 references.) (LRW)

Reports on the use of stemming for Slovene language documents and queries in free-text retrieval systems and demonstrates that an appropriate stemming algorithm results in an increase in retrieval effectiveness when compared with nonstemming processing. A comparison is made with stemming of English versions of the same documents and queries. (24…

Response time in large, inverted file document retrieval systems is determined by time required to access files of document identifiers on disk and process a Boolean search request. A specialized computer system has been devised that can perform a complicated sample search involving 70 terms and over 60,000 document references 12 to 60 times…