Describes a study that investigated document retrieval relevance based on document length in an experimental text collection. Topics include term weighting and document ranking, retrieval strategies such as the vector-space cosine match, and a modified technique called the pivoted cosine normalization. (LRW)

Describes a Delphi study conducted to determine factors that affect the process of routing and assigning reference questions received electronically by digital reference services, both to experts within the service and between services. Fifteen factors were determined, by expert consensus, to be important at the conclusion of this study.…

Presents a new method to improve the performance of query processing in a spatial database. Experiments demonstrated that performance of database systems can be improved because both the number of objects accessed and number of objects requiring detailed inspection are much less than those in the previous approach. (AEF)

Describes the architecture and functioning of a system developed specifically for text processing applications--such as information retrieval--that can benefit from structural comparisons between elements of text, such as queries and abstracts. The general ways in which the system performs matches and the ways in which this objective influenced…

Presents a manually constructed knowledge representation aimed at increasing the effectiveness of information retrieval systems. The framework of first order theories is used to analyze the properties of this new structure. The analysis demonstrates that the retrieval function takes term dependencies into account and distinguishes between…

Describes a system based on a probabilistic inference network retrieval model that was used to study the retrieval effectiveness benefits of combining types of document and query information that are found in typical commercial databases and information services. Multiple document representations, multiple index representations, and multiple query…

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…

Describes an information retrieval methodology based on relevance weighting of search terms in pairs of documents. The vector space model of information retrieval is reviewed, the Bayesian model of text retrieval is discussed, and an automatic implementation of weight estimation using the Medline database is described. (16 references) (LRW)

Presents a logical analysis of the characteristics of indexing and their effects on retrieval. The foundational questions of performance evaluation and the basic quantitative performance measures for binary noninteractive retrieval systems are established. The effects of indexing devices, indexing exhaustivity, specificity, correctness, and…

Explores the theory of psychological relevance and its relationship to information retrieval, and provides an extended example. Topics discussed include information need, the search process, the nature of information, topical relevance, relevance judgments and retrieval testing, information retrieval and bibliometrics, and suggestions for further…

Discussion of the role of Boolean logic in the information retrieval process focuses on a study that investigated the optimization of search logic for the MEDLINE database. Measures of retrieval effectiveness are discussed, the relationship of weighting schema and the logical schema is considered, and further investigations are suggested. (17…

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…

Explores similarities or dissimilarities between citation-semantic and analytic indexing based on a study of records in the Science Citation Index and MEDLINE databases on antibiotic resistance in pneumonia. Concludes that disparate indexing terms may be an advantage for better recall and precision in information retrieval. (Contains 42…

Content-based image retrieval is based on the idea of extracting visual features from images and using them to index images in a database. Proposes similarity measures and an indexing algorithm based on information theory that permits an image to be represented as a single number. When used in conjunction with vectors, this method displays…

Describes the design of an information retrieval system that permits the personalization of a search by developing a user profile in order to reduce noise and increase the number of relevant items retrieved. The preorientation system is explained and an example using full-text natural language processing tools is presented. (Author/LRW)