Search (27 results, page 1 of 2)

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Abstract

This article discusses how samples of records for laboratory IR experiments on OPACs can be constructed so that results obtained from different experiments can be compared. The literature on laboratory IR experiments seems to indicate that the retrieval effectiveness (recall and precision) is affected by the way the samples of records for such experiments are generated. Especially the amount of records and the subject area coverage of the records seems to affect the retrieval effectiveness. This article contains suggestions for the construction of samples for laboratory IR experiments on OPACs and demonstrates that the retrieval effectiveness is affected by different sample size and composition.

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Content

Enthält Beiträge von: FUGMANN, R.: Obstacles to progress in mechanized subject access and the necessity of a paradigm change; TELL, B.: On MARC and natural text searching: a review of Pauline Cochrane's inspirational thinking grafted onto a Swedish spy on library matters; KING, D.W.: Blazing new trails: in celebration of an audacious career; FIDEL, R.: The user-centered approach; SMITH, L.: Subject access in interdisciplinary research; DRABENSTOTT, K.M.: Web search strategies; LAM, V.-T.: Enhancing subject access to monographs in Online Public Access Catalogs: table of contents added to bibliographic records; JOHNSON, E.H.: Objects for distributed heterogeneous information retrieval

Date

22. 9.1997 19:16:05

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Content

"Most Web search engines accept natural language queries, perform some kind of fuzzy matching and produce ranked output, displaying first the documents that are most likely to be relevant. On the other hand, most library online public access catalogs (OPACs) an the Web are still Boolean retrieval systems that perform exact matching, and require users to express their search requests precisely in a Boolean search language and to refine their search statements to improve the search results. It is well-documented that users have difficulty searching Boolean OPACs effectively (e.g. Borgman, 1996; Ensor, 1992; Wallace, 1993). One approach to making OPACs easier to use is to develop a natural language search interface that acts as a middleware between the user's Web browser and the OPAC system. The search interface can accept a natural language query from the user and reformulate it as a series of Boolean search statements that are then submitted to the OPAC. The records retrieved by the OPAC are ranked by the search interface before forwarding them to the user's Web browser. The user, then, does not need to interact directly with the Boolean OPAC but with the natural language search interface or search intermediary. The search interface interacts with the OPAC system an the user's behalf. The advantage of this approach is that no modification to the OPAC or library system is required. Furthermore, the search interface can access multiple OPACs, acting as a meta search engine, and integrate search results from various OPACs before sending them to the user. The search interface needs to incorporate a method for converting the user's natural language query into a series of Boolean search statements, and for ranking the OPAC records retrieved. The purpose of this study was to develop a relevancyranking algorithm for a search interface to Boolean OPAC systems. This is part of an on-going effort to develop a knowledge-based search interface to OPACs called the E-Referencer (Khoo et al., 1998, 1999; Poo et al., 2000). E-Referencer v. 2 that has been implemented applies a repertoire of initial search strategies and reformulation strategies to retrieve records from OPACs using the Z39.50 protocol, and also assists users in mapping query keywords to the Library of Congress subject headings."

Source

Electronic library. 22(2004) no.2, S.112-120

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Abstract

By "recommending'' Furner refers to collaborative filtering where multiple user rankings of items are used to create a single new ranking for a user, or to a system itself generating rankings of items for its users. This would include document retrieval systems as a subset recommending systems in the second instance, but in the first would make document retrieval system and recommending system synonyms. Information seeking actions are classified either as evaluative (determining the worth of an item), recommending (expressing perceived worth), or informative (examining the content of an item). The task of the information retrieval system is to be to predict the particular ordering that the user would specify in a given context, given complete knowledge of the collection. Citations may be considered as the result of evaluative and recommending decisions by the author, and assigned index terms may be considered as the same sort of decisions by the indexer. The selection of relevant documents by a searcher from a list also involves evaluative and recommending decisions. This suggests that searchers should have the opportunity to bring multiple ranking techniques to bear.

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Abstract

This is the first part of a two-part article that reviews 25 years of published research findings on end-user searching in online information retrieval (IR) systems. In Part 1 (Markey, 2007), the author seeks to answer the following questions: What characterizes the queries that end users submit to online IR systems? What search features do people use? What features would enable them to improve on the retrievals they have in hand? What features are hardly ever used? What do end users do in response to the system's retrievals? Are end users satisfied with their online searches? Summarizing searches of online IR systems by the search features people use everyday makes information retrieval appear to be a very simplistic one-stop event. In Part 2, the author examines current models of the information retrieval process, demonstrating that information retrieval is much more complex and involves changes in cognition, feelings, and/or events during the information seeking process. She poses a host of new research questions that will further our understanding about end-user searching of online IR systems.

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Theme

Klassifikationssysteme im Online-Retrieval

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Abstract

The World Wide Web (simplified here to "Web") is well-known for its "point and click" graphical user interface (GUI) and hyperlink search and navigate capabilities. When OPACs are placed in this operational context, users can easily hyperlink from a bibliographic display to related search terms, class marks, or bibliographic records. This hyperlinking capability is not available in most conventional text-based OPACs. As more and more users undertake their searches on Web-based information retrieval systems such as OPACs, it is natural to ask, "Are Web-based OPACs more effective retrieval systems than their conventional predecessors?" This paper presents the findings of an experimental study which compared users' search performance, assessments of ease of use, and satisfaction with search results after use of a Web OPAC or its conventional counterpart. The primary questions addressed by this research center on the influence of two experimental factors, OPAC search interface style and search task level of difficulty, on the dependent variables: actual search performance, perceptions of ease of use, and user assessments of satisfaction with search results. It was hypothesized that Web OPACs would be assessed as easier to use and that they would outperform conventional OPACs when measured by actual search results and users' levels of satisfaction with search results. Web OPAC searchers outperformed Text OPAC searchers, but search task level of difficulty is a major determinant of search success. The study also found little association between searchers' level of satisfaction with results and actual search performance

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Abstract

This is the second part of a two-part article that examines 25 years of published research findings on end-user searching of online information retrieval (IR) systems. In Part 1, it was learned that people enter a few short search statements into online IR systems. Their searches do not resemble the systematic approach of expert searchers who use the full range of IR-system functionality. Part 2 picks up the discussion of research findings about end-user searching in the context of current information retrieval models. These models demonstrate that information retrieval is a complex event, involving changes in cognition, feelings, and/or events during the information seeking process. The author challenges IR researchers to design new studies of end-user searching, collecting data not only on system-feature use, but on multiple search sessions and controlling for variables such as domain knowledge expertise and expert system knowledge. Because future IR systems designers are likely to improve the functionality of online IR systems in response to answers to the new research questions posed here, the author concludes with advice to these designers about retaining the simplicity of online IR system interfaces.

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Abstract

Popular commercial on-line services such as Google, e-Bay, Amazon, and Netflix have evolved quickly over the last decade to help people find what they want, developing information retrieval strategies such as usefully ranked results, spelling correction, and recommender systems. Online library catalogs (OPACs), in contrast, have changed little and are notoriously difficult for patrons to use (University of California Libraries, 2005). Over the past year (June 2005 to the present), the Melvyl Recommender Project (California Digital Library, 2005) has been exploring methods and feasibility of closing the gap between features that library patrons want and have come to expect from information retrieval systems and what libraries are currently equipped to deliver. The project team conducted exploratory work in five topic areas: relevance ranking, auto-correction, use of a text-based discovery system, user interface strategies, and recommending. This article focuses specifically on the recommending portion of the project and potential extensions to that work.

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Abstract

Purpose - This paper aims at providing a robust, user-friendly and efficient navigation procedure in an online library catalog that is based on semantic information encapsulated within subject headings. Design/methodology/approach - The paper describes an interactive navigation procedure inside an online library catalog based on semantic information. The proposed approach is presented through a web-based, prototype application following the most recent trends of the semantic web such as AJAX technology and the web ontology language - OWL for encoding semantics. Findings - According to the proposed method, a GUI interface exposes the hierarchy of the subject headings employed within an OPAC, as well as all stated relations between such headings, as links that the user can follow, effectively traversing the ontology and formulating at the same time the actual query to the underlying OPAC. This act of interactive navigation through the library's assets aids searchers in accurately formulating their queries, by offering broader or narrower concepts for selection or indicating alternative or related concepts they might be initially unaware of. The augmented exposition of inter-relations between concepts provides multiple paths for information retrieval and enables searchers to fulfill their information needs in a faster, more efficient and intuitive manner. Practical implications - The paper includes implications for the development of modern, semantic web applications focused on the library domain. The novel approach of visualizing subject headings could be further extended to visualize a number of other conceptualizations of the library domain. Originality/value - This paper fulfils an identified need to take advantage of the "hidden knowledge" existing within the library domain but, for a number of reasons, is never exposed to the library users.

Theme

Verbale Doksprachen im Online-Retrieval

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Abstract

»Sacherschließung - können wir uns die noch leisten?« Angesichts des zunehmend geringeren Gesamtetats, der den Bibliotheken zur Verfügung steht, drängt sich diese Frage nahezu auf. Sacherschließung ist teuer und für das moderne Bibliothekswesen nur dann noch tragbar, wenn der Mitteleinsatz in einem angemessenen Verhältnis zum Ergebnis steht, das sich in der Leistungsfähigkeit des Produkts widerspiegelt. Im deutschsprachigen Raum trägt die SWD wesentlich zu einer effektiveren Sacherschließungsarbeit bei. Ihre Pflege und Weiterentwicklung ist jedoch mit einem enormen Aufwand gekoppelt, der nur mit einer entsprechenden Nutzung der Daten für das thematische Retrieval in den OPACs gerechtfertigt werden kann.

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Theme

Semantisches Umfeld in Indexierung u. Retrieval

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Theme

Klassifikationssysteme im Online-Retrieval

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Abstract

The Online Public Access Catalog (OPAC) is an information retrieval system characterized by short bibliographic records, mainly of books, journals, and audiovisual materials available in a particular library. This, coupled with a Boolean search interface and a heterogeneous user population with diverse needs, presents special problems for subject searching by end users. To perform effective subject searching in the OPAC system requires a wide range of knowledge and skills. Various approaches to improving the OPAC design for subject searching have been proposed and are reviewed in this entry. The trend toward Web-based OPAC interfaces and the developments in Internet and digital library technologies present fresh opportunities for enhancing the effectiveness of the OPAC system for subject searching.

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Abstract

In one form or another, from a mental list in the mind of the librarian, to book catalogs, card indexes, and online information retrieval systems, some type of meta access has existed to guide library users through library collections. Over the last 40 years, these constructs of paper and wood evolved into Online Public Access Catalogs (OPACs). When the catalog shifted out of drawers and off of three by five cards to become a networked, universally accessible entity, its role in the library shifted as well. The OPAC competes with the World Wide Web, metadata registries, search engines, and more sophisticated database structures for attention. Amongst this assortment of access mechanisms, the purpose of the OPAC has become muddled. The OPAC has now become one information source among many and one of a number of portals for accessing library collections and beyond.

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Abstract

Purpose - The purpose of this paper is to explore the information needs of one user group, public library fiction readers, in order to reveal a design of an online community at the local level. Examination of user-generated metadata can reveal new approaches to information architecture. Design/methodology/approach - A literature review into behaviors of virtual communities; surveying public library readers regarding search behavior characteristics - the survey included a sample "tagging" exercise to determine whether public library communities could create meaningful metadata for retrieval purposes. Findings - The use of relevance as an indicator of tag quality is flawed: in a survey, public library readers "tagged" the novel The Da Vinci Code. The resulting collection of tags provided a richer description of the book than did the social book-related web site www.librarything.com. Tag collections can be broken down into different categories, each reflecting a different "facet" of the novel: character, plot, subject/topic, setting, and genre. Faceted structure to tags enables users to choose the context of the tag to the novel. Research limitations/implications - This research is relevant in the world of social networking sites, online communities, or any other such system where users generate descriptive metadata. Examination of such metadata can reveal facets, which can guide the architect/librarian in the design of a versatile architecture. Originality/value - This research resulted in a manifold design for a public-library-based online community that allowed for the full expression of users' information needs. This research introduces a faceted structure to current approaches for user-generated metadata, adding versatility to search terms.

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Abstract

Subject searching is the most common but also the most conflictive searching for end user. The aim of this paper is to check how users expressions match subject headings and to prove if knowledge structure used in online catalogs enhances searching effectiveness. A bibliographic revision about difficulties in subject access and proposed methods to improve it is also presented. For the empirical analysis, transaction logs from two university libraries, online catalogs (CISNE and FAMA) were collected. Results show that more than a quarter of user queries are effective due to an alphabetical subject index approach and browsing through hypertextual links. 1. Introduction Since the 1980's, online public access catalogs (OPAC's) have become usual way to access bibliographic information. During the last two decades the technological development has helped to extend their use, making feasible the access for a whole of users that is getting more and more extensive and heterogeneous, and also to incorporate information resources in electronic formats and to interconnect systems. However, technology seems to have developed faster than our knowledge about the tasks where it has been applied and than the evolution of our capacities for adapting to it. The conceptual model of OPAC has been hardly modified recently, and for interacting with them, users still need to combine the same skills and basic knowledge than at the beginning of its introduction (Borgman, 1986, 2000): a) conceptual knowledge to translate the information need into an appropriate query because of a well-designed mental model of the system, b) semantic and syntactic knowledge to be able to implement that query (access fields, searching type, Boolean logic, etc.) and c) basic technical skills in computing. At present many users have the essential technical skills to make use, with more or less expertise, of a computer. This number is substantially reduced when it is referred to the conceptual, semantic and syntactic knowledge that is necessary to achieve a moderately satisfactory search. An added difficulty arises in subject searching, as users should concrete their unknown information needs in terms that the information retrieval system can understand. Many researches have focused an unskilled searchers' difficulties to enter an effective query. The mental models influence, users assumption about characteristics, structure, contents and operation of the system they interact with have been analysed (Dillon, 2000; Dimitroff, 2000). Another issue that implies difficulties is vocabulary: how to find the right terms to implement a query and to modify it as the case may be. Terminology and expressions characteristics used in searching (Bates, 1993), the match between user terms and the subject headings from the catalog (Carlyle, 1989; Drabensttot, 1996; Drabensttot & Vizine-Goetz, 1994), the incidence of spelling errors (Drabensttot and Weller, 1996; Ferl and Millsap, 1996; Walker and Jones, 1987), users problems

Theme

Semantisches Umfeld in Indexierung u. Retrieval

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Date

10. 9.2000 17:38:22

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Date

17. 8.2008 11:22:47

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Date

10. 9.2000 17:38:22