Search (29 results, page 1 of 2)

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Abstract

Despite early claims to the contemporary, thesauri continue to find use as access tools for information in the full-text environment. Their mode of use is changing, but this change actually represents an expansion rather than a contrdiction of their utility. Thesauri and similar vocabulary tools can complement full-text access by aiding users in focusing their searches, by supplementing the linguistic analysis of the text search engine, and even by serving as one of the tools used by the linguistic engine for its analysis. While human indexing contunues to be used for many databases, the trend is to increase the use of machine aids for this purpose. All machine-aided indexing (MAI) systems rely on thesauri as the basis for term selection. In the 21st century, the balance of effort between human and machine will change at both input and output, but thesauri will continue to play an important role for the foreseeable future

Date

22. 9.1997 19:16:05

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Abstract

Examines how far automation cluster analysis and association testing are relevant methods for smaller libraries in construction of search thesauri. Using WORDSTAR, a simple form of cluster analysis was tested, with satisfactory results in that the index terms formed clusters of a suitable size. The association test was used to elicit from users' natural language terms which can be used in the search thesaurus as entrance vocabulary. The test showed that users associated very differently in relation to the same stimuli words, with low overlap with terms used in the system's indexing. The results confirmed the need for better feedback. Concludes that while neither method can be used alone, a search thesauri which combine terms from the indexes and from users can be a powerful tool

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Abstract

Presents a framework for knowledge discovery and concept exploration. In order to enhance the concept exploration capability of knowledge based systems and to alleviate the limitation of the manual browsing approach, develops 2 spreading activation based algorithms for concept exploration in large, heterogeneous networks of concepts (eg multiple thesauri). One algorithm, which is based on the symbolic AI paradigma, performs a conventional branch-and-bound search on a semantic net representation to identify other highly relevant concepts (a serial, optimal search process). The 2nd algorithm, which is absed on the neural network approach, executes the Hopfield net parallel relaxation and convergence process to identify 'convergent' concepts for some initial queries (a parallel, heuristic search process). Tests these 2 algorithms on a large text-based knowledge network of about 13.000 nodes (terms) and 80.000 directed links in the area of computing technologies

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Abstract

In this article, we report research on an algorithmic approach to alleviating search uncertainty in a large information space. Grounded on object filtering, automatic indexing, and co-occurence analysis, we performed a large-scale experiment using a parallel supercomputer (SGI Power Challenge) to analyze 400.000+ abstracts in an INSPEC computer engineering collection. Two system-generated thesauri, one based on a combined object filtering and automatic indexing method, and the other based on automatic indexing only, were compaed with the human-generated INSPEC subject thesaurus. Our user evaluation revealed that the system-generated thesauri were better than the INSPEC thesaurus in 'concept recall', but in 'concept precision' the 3 thesauri were comparable. Our analysis also revealed that the terms suggested by the 3 thesauri were complementary and could be used to significantly increase 'variety' in search terms the thereby reduce search uncertainty

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Abstract

Open system protocols for search and retrieval have not provided explicit ways in which to implement thesaurus-aided searching. A number of different approaches within the existing protocols, as well as a proposed service, are evaluated. A general approach to implementing thesaurus-aided searching, particularly during consultation of a thesaurus, requires an entirely new service, whose main features are described

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Abstract

This article introduces a new concept and technique for information retrieval called 'colinked descriptors'. Borrowed from an analogous idea in bibliometrics - cocited references - colinked descriptors provide a theory and method for identifying search terms that, by hypothesis, will be superior to those entered initially by a searcher. The theory suggests a means of moving automatically from 2 or more initial search terms, to other terms that should be superior in retrieval performance to the 2 original terms. A research project designed to test this colinked descriptor hypothesis is reported. The results suggest that the approach is effective, although methodological problems in testing the idea are reported. Algorithms to generate colinked descriptors can be incorporated easily into system interfaces, front-end or pre-search systems, or help software, in any database that employs a thesaurus. The potential use of colinked descriptors is a strong argument for building richer and more complex thesauri that reflect as many legitimate links among descriptors as possible

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Abstract

Reports an algorithmic approach to the automatic generation of thesauri for electronic community systems. The techniques used included terms filtering, automatic indexing, and cluster analysis. The testbed for the research was the Worm Community System, which contains a comprehensive library of specialized community data and literature, currently in use by molecular biologists who study the nematode worm. The resulting worm thesaurus included 2709 researchers' names, 798 gene names, 20 experimental methods, and 4302 subject descriptors. On average, each term had about 90 weighted neighbouring terms indicating relevant concepts. The thesaurus was developed as an online search aide. Tests the worm thesaurus in an experiment with 6 worm researchers of varying degrees of expertise and background. The experiment showed that the thesaurus was an excellent 'memory jogging' device and that it supported learning and serendipitous browsing. Despite some occurrences of obvious noise, the system was useful in suggesting relevant concepts for the researchers' queries and it helped improve concept recall. With a simple browsing interface, an automatic thesaurus can become a useful tool for online search and can assist researchers in exploring and traversing a dynamic and complex electronic community system

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Abstract

Discusses the various functions which a thesaurus can have. Highlights the main function of a thesaurus in vocabulary control, eliminating natural language ambiguity and providing consistency of indexing, and serving as an aid in the searching process. Further discusses the function of a search thesaurus in serving as a user's aid in full text systems and in free indexing systems, and the additional function of an online thesaurus integrated with an online database, that of a vocabulary master file. Notes also how a thesaurus can function as a switching language or intermediary lexicon in multidatabase systems

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Date

15. 3.2000 10:22:37

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Date

1. 8.1996 22:01:00

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Date

1. 8.1996 22:01:00

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Abstract

Specifications are presented for software designed to support manual development and maintenance of information retrieval thesauri. The specifications are intended to support both evaluation of existing packages for acquisition and design of custom software. Specialized requirements of thesaurus support are emphasized over more general database management requirements. Requirements for integration with larger systems and for the user interface are summarized. Relationships specified by the ANSI standard should be supported, and the relationships should be validated to avoid introduction of conflicting relationships. Flexibility in availability of note and date fields is important, and where required, term classifications should be available. Maintenance procedures should include provision for feedback on the impact of changes, as well as appropriate levels of approval for changes. A wide variety of online displays and printed reports are required, including but not limited to alphabetical, hierarchical, and rotated. In addition, it is desirable to be absle to search the thesaurus database with such capabilities as Boolean logic and proximity operators

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Abstract

Thesauri are valuable structures for Information Retrieval systems. A thesaurus provides a precise and controlled vocabulary which serves to coordinate dacument indexing and document retrieval. In both indexing and retrieval, a thesaurus may be used to select the most appropriate terms. Additionally, the thesaurus can assist the searcher in reformulating search strategies if required. Examines the important features of thesauri. This should allow the reader to differentiate between thesauri. Next, a brief overview of the manual thesaurus construction process is given. 2 major approaches for automatic thesaurus construction have been selected for detailed examination. The first is on thesaurus construction from collections of documents,a nd the 2nd, on thesaurus construction by merging existing thesauri. These 2 methods were selected since they rely on statistical techniques alone and are also significantly different from each other. Programs written in C language accompany the discussion of these approaches

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Abstract

For more than thirty years thesauri have been valuable tools in information retrieval. Originally, the basic function of the thesauri was to help the indexer to transform concepts and their relationships, as expressed in the language of documents, into the more regularised indexing language of catalogues and databases. In the nineties another important purpose of the thesauri is to guide the searcher to the best search terms. In spite of the new role, the design of the thesauri has remained more or less stable. This paper explores the demands which are put on the thesauri in relation to searching. Findings are presented in the form of generalisations and moreover illustrated in relation to a real-life situation. Suggestions for improved functionality are presented in the form of a prototype of a thesaurus record. The new role as a conceptual searching tool is also influencing the construction process. Therefore, the paper ends up with a discussion of new methods for thesaurus construction

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Abstract

The need for thesauri to help users in their search for information in online information systems has been discussed for several decades. Many wide-ranging contributions have been made to solve this problem. Nevertheless, investigation is needed to design a thesaurus structure based on what is relevant for users and generators of information within a specific subject domain. Explores the possibility of creating a thesaurus from the cognitive viewpoint. This approach is based on a system that organizes its representation of knowledge or its classification as closely as possible to the authors' and users' images of the subject domain with the objective of increasing the interaction between users and texts, and thus the communication in a given information retrieval system. Discourse analysis is used as a main method to identify the categories and its relevance for building such a structure is discussed

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Source

Information und Märkte: 50. Deutscher Dokumentartag 1998, Kongreß der Deutschen Gesellschaft für Dokumentation e.V. (DGD), Rheinische Friedrich-Wilhelms-Universität Bonn, 22.-24. September 1998. Hrsg. von Marlies Ockenfeld u. Gerhard J. Mantwill

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Source

Information und Märkte: 50. Deutscher Dokumentartag 1998, Kongreß der Deutschen Gesellschaft für Dokumentation e.V. (DGD), Rheinische Friedrich-Wilhelms-Universität Bonn, 22.-24. September 1998. Hrsg. von Marlies Ockenfeld u. Gerhard J. Mantwill

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Source

Information und Märkte: 50. Deutscher Dokumentartag 1998, Kongreß der Deutschen Gesellschaft für Dokumentation e.V. (DGD), Rheinische Friedrich-Wilhelms-Universität Bonn, 22.-24. September 1998. Hrsg. von Marlies Ockenfeld u. Gerhard J. Mantwill

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Source

Revista Española de Documentaçion Cientifica. 22(1999) no.1, S.34-49

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Abstract

Once the library has been through a process of transition from traditional library procedures to automated ones, natural language searching became a necessity for both indexers and searchers. Therefore, aside from the precoordinated classified catalogue we started to build a dictionary of terms in order to make postcoordinate search possible in keeping with the UDC notations assigned to each bibliographic record. After a while we came to the conclusion that the dictionary needed a control of its terms so that synonymous concepts and semantic ambuguities be avoided. The project presented in this paper shows how reality imposed the improvement of the quality of indexing and hence of the searching possibilities. Is also shows the reasons why we consider a multilingual thesaurus based on UDC an ideal indexing and searching device. The experiment applied on class 8 of UDC illustrates the way the UDC tables can be quite successfully used in building a thesaurus due to their qulities and how their limitations can be overcome by a thesaurus. An appendix to the paper contains a sample of the multilingual thesaurus given in both alphabetical and systematic layouts