Describes a hierarchical text database model and defines an algebra based on concordance lists. The algebra is presented as a theoretical model to define both a conceptual schema for the database and search protocols for database implementation. Several retrieval examples are included. (19 references) (MES)

Reviews selected research on the performance of bibliographic and full-text databases. A mathematical model for clarification of the relationship between user behavior and the performance measures of recall and precision is presented. (five references) (MES)

Describes a new signature file method, called the multiorganizational scheme, for accessing information from large databases containing both formatted and free-text data. Implementation issues are discussed, and computational results based on a mathematical model are presented, as well as results using a library database. (43 references) (MES)

Introduces a hypertext data model for textual databases in which the text is divided into a syntactic structure, which describes the relationships of the text parts, and an access structure, which is generated from the syntactic structure by users' queries. Implementation considerations for the structuring component, retrieval component, and…

Based on evaluations of 1,025 CD-ROM products, this article summarizes trends in (1) growth of commercially available CD-ROM titles; (2) types and subjects of products produced; (3) update options; (4) hardware systems CD-ROMs are designed to run on; (5) prices; and (6) multimedia products. Possible future developments that could revolutionize…

Provides an overview of methods for improving the effectiveness of Boolean retrieval systems, including document clustering, relevance feedback, weighted term searching, ranked output, and fuzzy set theory. The discussion of experimental studies with the SMART and SIRE systems focuses on the implementation and results of these methods. (69…

Describes the PADOK-II project in Germany, which was designed to give information on the effects of linguistic algorithms on retrieval in a full-text database, the German Patent Information System (GPI). Relevance assessments are discussed, statistical evaluations are described, and searches are compared for the full-text section versus the…

Describes a project that was designed to test the relative efficacy of index terms and full-text for the retrieval of documents in MEDLINE journals. Precision and relevance of citations retrieved from full-text databases versus bibliographic databases is discussed, and the addition of MEDLINE indexing to enhance full-text medical journals is…

Describes techniques used for information retrieval from free-text or document databases and presents a new approach based on signature files, or representations of documents, called the Map Array Signature (MAS) method. False drops are discussed, and results of experiments are compared to Robert's Superimposed Coding method. (20 references) (LRW)

This progress report presents findings from a failure analysis of two full-text computer-assisted legal research systems, Lexis and Westlaw. Linguistic analyses of unretrieved documents and false drops are discussed, and examples of natural language phenomena that affect Boolean retrieval system performance are examined. (Author/LRW)

Reports on the validity of the Multiple Poisson (nP) model of word distribution in full-text document collections. A practical algorithm for determining whether a certain word is distributed according to an nP distribution and the results of a test of this algorithm in three different document collections are described. (14 references) (KRN)

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.…

Discusses results of a survey designed to investigate the role of technology in research, both from the instructor and student standpoints. Results indicate a wide discrepancy between instructor and student expectations and methods, as well as an increasing demand on the part of students for full-text sources. (Author/LRW)

Suggests ways to increase precision when searching full text files on BRS, Mead Data Central and DIALOG. All of the techniques are based on achieving repetition of central concepts as expressed in natural language. Schematic representations of strategies and sample searches on each of the three systems are provided. (10 references) (CLB)

Analyzes different kinds of reformulations used in information retrieval systems where full text databases are accessed through natural language queries. Tests of these reformulations on large full text databases managed by the Syntactic and Probabilistic Indexing and Retrieval of Information in Texts (SPIRIT) system are described, and an expert…