Search (332 results, page 3 of 17)

0.030339649 = product of:
  0.121358596 = sum of:
    0.121358596 = weight(_text_:headings in 1232) [ClassicSimilarity], result of:
      0.121358596 = score(doc=1232,freq=2.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.37528375 = fieldWeight in 1232, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.0546875 = fieldNorm(doc=1232)
  0.25 = coord(1/4)

Abstract

This paper examines some traditional information searching methods and their role in Hungarian OPACs. What challenges are there in the digital and online environment? How do users work with them and do they give users satisfactory results? What kinds of techniques are users employing? In this paper I examine the user interfaces of UDC, thesauri, subject headings etc. in the Hungarian library. The key question of the paper is whether a universal system or local solutions is the best approach for searching in the digital environment.

0.030339649 = product of:
  0.121358596 = sum of:
    0.121358596 = weight(_text_:headings in 156) [ClassicSimilarity], result of:
      0.121358596 = score(doc=156,freq=2.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.37528375 = fieldWeight in 156, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.0546875 = fieldNorm(doc=156)
  0.25 = coord(1/4)

Abstract

Controlled vocabulary and subject headings in OPAC records have proven to be useful in improving search results. The authors used a survey to gather information about librarian opinions and professional use of controlled vocabulary. Data from a range of backgrounds and expertise were examined, including academic and public libraries, and technical services as well as public services professionals. Responses overall demonstrated positive opinions of the value of controlled vocabulary, including in reference interactions as well as during bibliographic instruction sessions. Results are also examined based upon factors such as age and type of librarian.

0.026005413 = product of:
  0.10402165 = sum of:
    0.10402165 = weight(_text_:headings in 2372) [ClassicSimilarity], result of:
      0.10402165 = score(doc=2372,freq=2.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.32167178 = fieldWeight in 2372, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.046875 = fieldNorm(doc=2372)
  0.25 = coord(1/4)

Abstract

Research conducted in the early 80's has shown that subject access is still one of the most dominant approaches in OPACs. However, while some of the subject searches result in no recall, others often retrieve so much that users are discouraged to proceed further. These and other problems were investigated and solutions were found in improving search methods (such as word stemming, extending search to full bibliographical record and providing end user thesaurus) and indexing techniques (such as ny enhancing subject headings with table of contents and back of the book indexes or by traditional systems). More recent research indicates that the real answer to the question of 'precision without sacrificing recall' lies in the developing 'user friendly novel interfaces' and also in designing 'knowledge based systems', wherein sers would not be expected to learn query formulation or even to be familiar with the indexing language of the system. Several interesting studies and research projects on the subject have produced a whole gamut of information, but one can still visualise the evolving trends of research vis-a-vis their future prospects as possible solutions

0.026005413 = product of:
  0.10402165 = sum of:
    0.10402165 = weight(_text_:headings in 3678) [ClassicSimilarity], result of:
      0.10402165 = score(doc=3678,freq=2.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.32167178 = fieldWeight in 3678, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.046875 = fieldNorm(doc=3678)
  0.25 = coord(1/4)

Abstract

Subject queries were extracted from 3 universities' online catalogues and analysed to determine the extend to which they matched subject headings in the LCSH. Computer analyses show that nearly 25% of the subject queries entered by online catalogue users are exact matches of LCSH. Yet, manual analyses show that, even though a user matches or closely matches LCSH-mr, the citations retrieved by this vocabulary are not necessarily satisfactory. Sometimes the closest LCSH-mr is not at all pertinent to a user's topic of interest. This study presents reasons why close matches of LCSH-mr are not always satisfactory and suggests approaches to finding the best matches of the catalogue's controlled vocabulary

0.026005413 = product of:
  0.10402165 = sum of:
    0.10402165 = weight(_text_:headings in 7001) [ClassicSimilarity], result of:
      0.10402165 = score(doc=7001,freq=2.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.32167178 = fieldWeight in 7001, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.046875 = fieldNorm(doc=7001)
  0.25 = coord(1/4)

Abstract

The paper will discuss the impact on cataloging standards and bibliographic data formats and will point into the direction of a new cataloging environment with different access point accordings to the information requirements of the users. The present subject headings and classification schemes used to index library materials have to be considered obsolete. The aim must be the integration of existing thesauri accepted and used by the acedemic community by utilizing a 'meta language' as a software engineering tool. This 'meta language' will offer access points by means of different facets focusing the information stored, and these facets will be interactivelyselected by the user supporting the demands of his academic field and retrieval practice

0.026005413 = product of:
  0.10402165 = sum of:
    0.10402165 = weight(_text_:headings in 6796) [ClassicSimilarity], result of:
      0.10402165 = score(doc=6796,freq=2.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.32167178 = fieldWeight in 6796, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.046875 = fieldNorm(doc=6796)
  0.25 = coord(1/4)

Abstract

Reports results of analysis and comparison of full level displays of bibliographic records in 36 North American online catalogues for 5 monographs, for both layout and content, with the ISBD and traditional catalogue carddisplay practive for headings and tracings. Presents a taxonomy of display characteristics found in the sample, including: completeness; visual layout; data sequence; label specifity; and integration of description and access points. Discusses the relationship of display technology and practice to current standards for creating catalogue records, emphasizing the need for content standards reflecting the modular nature of computerized records. Concludes that future OPAC displays will resemble card catalogue records less and less, both visually and in structure and content, and points to the need for further research to gather the information needed to make the transition as smooth as possible

0.026005413 = product of:
  0.10402165 = sum of:
    0.10402165 = weight(_text_:headings in 2788) [ClassicSimilarity], result of:
      0.10402165 = score(doc=2788,freq=2.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.32167178 = fieldWeight in 2788, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.046875 = fieldNorm(doc=2788)
  0.25 = coord(1/4)

Abstract

Reports results of an analysis of 205 randomly selected records from the OCLC OLUC, to test the assumption that online catalogues have greatly improved subject searching capabilities, over card catalogues, by making other fields in the records searchable as subject access points (SAPs). Results showed considerable overlap (duplication) among the SAPs provided by the title, subject heading and classification number fields. On average, little more than 4 unique, unduplicated access points were found per record. Where title and classification number fields do add some access points not provided by subject headings, the increase is less than many librarians might be expected. Suggests that OPACs might outperform catalogues more in precision than in recall by allowing greater discrimination in searching; terms from different fields may be combined; titles offer greater specifity; searches can be limited by date, language or other criteria

0.026005413 = product of:
  0.10402165 = sum of:
    0.10402165 = weight(_text_:headings in 12) [ClassicSimilarity], result of:
      0.10402165 = score(doc=12,freq=2.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.32167178 = fieldWeight in 12, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.046875 = fieldNorm(doc=12)
  0.25 = coord(1/4)

Abstract

According to the Calhoun report, library operations that are not digital, that do not result in resources that are remotely accessible, that involve professional human judgement or expertise, or that require conceptual categorization and standardization rather than relevance ranking of keywords, do not fit into its proposed "leadership" strategy. This strategy itself, however, is based on an inappropriate business model - and a misrepresentation of that business model to begin with. The Calhoun report draws unjustified conclusions about the digital age, inflates wishful thinking, fails to make critical distinctions, and disregards (as well as mischaracterizes) an alternative "niche" strategy for research libraries, to promote scholarship (rather than increase "market position"). Its recommendations to eliminate Library of Congress Subject Headings, and to use "fast turnaround" time as the "gold standard" in cataloging, are particularly unjustified, and would have serious negative consequences for the capacity of research libraries to promote scholarly research.

0.026005413 = product of:
  0.10402165 = sum of:
    0.10402165 = weight(_text_:headings in 350) [ClassicSimilarity], result of:
      0.10402165 = score(doc=350,freq=2.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.32167178 = fieldWeight in 350, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.046875 = fieldNorm(doc=350)
  0.25 = coord(1/4)

Abstract

The use of title words, the combination of these through the use of logic operators, and the possibility of truncating them when carrying out subject searches, are some of the search options that have been incorporated into the online catalog. Several arguments in favor of these options have been expressed which state that they represent an approach for the use of natural language and that they facilitate information retrieval. However, expressed arguments against them that support the necessity of using controlled language to obtain more precision in search results also exist. This paper reports the main results from a study whose objective was to compare advantages and disadvantages of retrieval by keywords from the title and by subject headings included in the records of LIBRUNAM, an online catalog containing records for English and Spanish items at the National Autonomous University of Mexico.

0.026005413 = product of:
  0.10402165 = sum of:
    0.10402165 = weight(_text_:headings in 651) [ClassicSimilarity], result of:
      0.10402165 = score(doc=651,freq=2.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.32167178 = fieldWeight in 651, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.046875 = fieldNorm(doc=651)
  0.25 = coord(1/4)

Abstract

This paper examines the need for increased subject catalog access to imaginative literature, focusing on the environment of the academic/research library. New trends in scholarship have created more need for such subject access. We can develop a basis for subject access to imaginative literature by examining the historical treatment of imaginative literature and by drawing upon the past and present work of librarians, other information professionals such as indexers, and literary scholars. While many information professionals have recognized a need for increased subject access to individual works of imagination, there has been no clear consensus on how to do this. This paper represents a step forward in that direction, showing how we might use LCSH to express the themes or topics of an imaginative work. It is important that such subject access be multi-dimensional, identifying both concrete and abstract levels of meaning. Using The Scarlet Letter by Nathaniel Hawthorne as an example, it is demonstrated how LC-type subject headings using LC subject terms with genre/form subdivisions can be developed.

0.02451814 = product of:
  0.09807256 = sum of:
    0.09807256 = weight(_text_:headings in 2799) [ClassicSimilarity], result of:
      0.09807256 = score(doc=2799,freq=4.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.30327508 = fieldWeight in 2799, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.03125 = fieldNorm(doc=2799)
  0.25 = coord(1/4)

Content

Inhalt: Introduction -- Focusing on user needs :new ways of subject access in Czechia -- Subject analysis and indexing :an "Italian version" of the analytico-synthetic model -- Subject search in Italian OPACs :an opportunity in waiting? -- Semiautomatic merging of two universal thesauri :the case of Estonia -- 20 years SWD :German subject authority data prepared for the future -- Mixed translations of the DDC :design, usability, and implications for knowledge organization in multilingual environments -- Animals belonging to the emperor :enabling viewpoint warrant in classification -- Dewey in Sweden :leaving SAB after 87 years -- Enhancing information services using machine-to-machine terminology services -- Social bookmarking and subject indexing -- Social indexing at the Stockholm Public Library -- The Nuovo Soggettario Thesaurus :structural features and web application projects -- Jzyk Hasel Przedmiotowych Biblioteki Narodowej (National Library of Poland Subject Headings) :from card catalogs to Digital Library :some questions about the future of a Local Subject Heading Systems in the changing world of information retrieval -- FAST headings as tags for WorldCat

0.021956919 = product of:
  0.087827675 = sum of:
    0.087827675 = weight(_text_:und in 2060) [ClassicSimilarity], result of:
      0.087827675 = score(doc=2060,freq=6.0), product of:
        0.1478073 = queryWeight, product of:
          2.217899 = idf(docFreq=13141, maxDocs=44421)
          0.06664293 = queryNorm
        0.5942039 = fieldWeight in 2060, product of:
          2.4494898 = tf(freq=6.0), with freq of:
            6.0 = termFreq=6.0
          2.217899 = idf(docFreq=13141, maxDocs=44421)
          0.109375 = fieldNorm(doc=2060)
  0.25 = coord(1/4)

Series

Zeitschrift für Bibliothekswesen und Bibliographie: Sonderh.52

Source

Der Online-Publikumskatalog der Universitätsbibliothek Düsseldorf: methodische Erkenntnisse und Erfahrungen, OPAC-Kolloquium am 27.-28.11.1989. Hrsg.: G. Gattermann

0.02173171 = product of:
  0.08692684 = sum of:
    0.08692684 = weight(_text_:und in 1886) [ClassicSimilarity], result of:
      0.08692684 = score(doc=1886,freq=18.0), product of:
        0.1478073 = queryWeight, product of:
          2.217899 = idf(docFreq=13141, maxDocs=44421)
          0.06664293 = queryNorm
        0.58810925 = fieldWeight in 1886, product of:
          4.2426405 = tf(freq=18.0), with freq of:
            18.0 = termFreq=18.0
          2.217899 = idf(docFreq=13141, maxDocs=44421)
          0.0625 = fieldNorm(doc=1886)
  0.25 = coord(1/4)

Abstract

Seit Frühjahr 2004 ist Dandelon.com als neues, offenes, internationales Wissenschaftsportal in Betrieb. Erste Retrieval-Tests bescheinigen deutlich bessere Suchergebnisse als in herkömmlichen OPACs oder Verbundsystemen. Seine Daten stammen aus intelligentCAPTURE und Bibliothekskatalogen. intelligentCAPTURE erfasst Content über Scanning oder File-Import oder Web-Spidering und indexiert nach morphosyntaktischen und semantischen Verfahren. Aufbereiteter Content und Indexate gehen an Bibliothekssysteme und an dandelon.com. Dandelon.com ist kostenlos zugänglich für Endbenutzer und ist zugleich Austauschzentrale und Katalogerweiterung für angeschlossene Bibliotheken. Neue Inhalte können so kostengünstig und performant erschlossen werden.

0.021671178 = product of:
  0.08668471 = sum of:
    0.08668471 = weight(_text_:headings in 2009) [ClassicSimilarity], result of:
      0.08668471 = score(doc=2009,freq=2.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.26805982 = fieldWeight in 2009, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.0390625 = fieldNorm(doc=2009)
  0.25 = coord(1/4)

Content

Enthält die Beiträge: TYCKOSON, D.A.: Enhancing access to information: building catalogs for the future; TYCKOSON, D.A.: The twenty-first century limited: desinging catalogs for the next century; DWYER, J.: Bibliographic records enhancement: from the drawing board to the catalog screen; SYRACUSE, R.O. u. R.K. POYER: Enhancing access to the library's collections: a view from an academic health center library; STUDWELL, W.E.: Of eggs and baskets: getting more access out of LC Subject Headings in an online environment; STEPHENS, I.E.: Getting more out of call numbers: displaying holdings, locations and circulation status; MICCO, M.: The next generation of online public access catalogs: a new look at subject access using hypermedia; SLOAN, B.G.: Remote access: design implications for the online catalog; ENGEL, G.: User instruction for access to catalogs and database on the Internet; BARNES, S. u. J. McCUE: Linking library records to bibliographic databases: an analysis of common data elements in BIOSIS, Agricola and the OPAC; HARWOOD, R.: Adding a nonlibrary campus collection to the library database; CARTER, K., H. OLSEN u. S. AQUILA: Bulk loading of records for microform sets into the online catalogue; DYKEMAN, A. u. J. ZIMMERMAN: The Georgia Institute of Technology Electronic Library: issues to consider; MOLHOLT, P. u. K. FORSYTHE: Opening up information access through the electronic catalog

0.021671178 = product of:
  0.08668471 = sum of:
    0.08668471 = weight(_text_:headings in 2801) [ClassicSimilarity], result of:
      0.08668471 = score(doc=2801,freq=2.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.26805982 = fieldWeight in 2801, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.0390625 = fieldNorm(doc=2801)
  0.25 = coord(1/4)

Abstract

Subject access to bibliographic data supported by knowledge organization systems, such as subject headings and classification, plays an important role in ensuring the quality of library catalogues. It is generally acknowledged that users have a strong affinity to subject browsing and searching and are inclined tofollow meaningful links between resources. Research studies, however, show that library OPACs are not designed to support or make good use of subject indexes and their underlying semantic structure. A project entitled OPAC semantici was initiated in 2003 by a number of Italian subject specialists and the Italian "Research Group on Subject Indexing" (GRIS) with a goal to analyse and evaluate subject access in Italian library catalogues through a survey of 150 OPACs. Applying the same methodology, a follow-up survey to assess whether any improvement had taken place was conducted five years later, in spring 2008. Analysis of these two surveys indicated that there was a slight improvement. The authors discuss the results of these two surveys, analyse the problems in subject searching in OPACs and explain the recommendations for subject searching enhancement put forward by GRIS. Using the example of Italian OPACs, the authors will attempt to outline some requirements for a subject searching interface and explain how this can be achieved through authority control.

0.021671178 = product of:
  0.08668471 = sum of:
    0.08668471 = weight(_text_:headings in 307) [ClassicSimilarity], result of:
      0.08668471 = score(doc=307,freq=2.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.26805982 = fieldWeight in 307, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.0390625 = fieldNorm(doc=307)
  0.25 = coord(1/4)

Abstract

The construction and updating of indexing languages depend on the organization of their hierarchical structures in order to determine the classification of related terms and, above all, to allow a constant updating of vocabulary, a condition for knowledge evolution. The elaboration of an indexing language for online catalogs of libraries' networks is important considering the diversity and specificity of knowledge areas. From this perspective, the present paper reports on the work of a team of catalogers and researchers engaged in the construction of a hierarchical structure of an indexing language for an online catalog of a university library's network. The work on hierarchical structures began by defining the categories and subcategories that form the indexing language macrostructure by using the parameters of the Library of Congress Subject Headings , the National Library Terminology and the Vocabulary of the University of São Paulo Library's system. Throughout the stages of the elaboration process of the macrostructure, difficulties and improvements were observed and discussed. The results enabled the assessment of the hierarchical structures of the languages used in the organization of the superordinate and subordinate terms, which has contributed to the systematization of operational procedures contained in an indexing language manual for online catalogs of libraries.

0.021671178 = product of:
  0.08668471 = sum of:
    0.08668471 = weight(_text_:headings in 148) [ClassicSimilarity], result of:
      0.08668471 = score(doc=148,freq=2.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.26805982 = fieldWeight in 148, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.0390625 = fieldNorm(doc=148)
  0.25 = coord(1/4)

Abstract

Documents in digital and paper libraries may be arranged, based on their topics, in order to facilitate browsing. It may seem intuitively obvious that ordering documents by their subject should improve browsing performance; the results presented in this article suggest that ordering library materials by their Gray code values and through using links consistent with the small world model of document relationships is consistent with improving browsing performance. Below, library circulation data, including ordering with Library of Congress Classification numbers and Library of Congress Subject Headings, are used to provide information useful in generating user-centered document arrangements, as well as user-independent arrangements. Documents may be linearly arranged so they can be placed in a line by topic, such as on a library shelf, or in a list on a computer display. Crossover links, jumps between a document and another document to which it is not adjacent, can be used in library databases to allow additional paths that one might take when browsing. The improvement that is obtained with different combinations of document orderings and different crossovers is examined and applications suggested.

0.021453371 = product of:
  0.085813485 = sum of:
    0.085813485 = weight(_text_:headings in 3768) [ClassicSimilarity], result of:
      0.085813485 = score(doc=3768,freq=4.0), product of:
        0.32337824 = queryWeight, product of:
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.06664293 = queryNorm
        0.2653657 = fieldWeight in 3768, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          4.8524013 = idf(docFreq=942, maxDocs=44421)
          0.02734375 = fieldNorm(doc=3768)
  0.25 = coord(1/4)

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

0.020488854 = product of:
  0.08195542 = sum of:
    0.08195542 = weight(_text_:und in 475) [ClassicSimilarity], result of:
      0.08195542 = score(doc=475,freq=4.0), product of:
        0.1478073 = queryWeight, product of:
          2.217899 = idf(docFreq=13141, maxDocs=44421)
          0.06664293 = queryNorm
        0.5544748 = fieldWeight in 475, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          2.217899 = idf(docFreq=13141, maxDocs=44421)
          0.125 = fieldNorm(doc=475)
  0.25 = coord(1/4)

0.020488854 = product of:
  0.08195542 = sum of:
    0.08195542 = weight(_text_:und in 1402) [ClassicSimilarity], result of:
      0.08195542 = score(doc=1402,freq=4.0), product of:
        0.1478073 = queryWeight, product of:
          2.217899 = idf(docFreq=13141, maxDocs=44421)
          0.06664293 = queryNorm
        0.5544748 = fieldWeight in 1402, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          2.217899 = idf(docFreq=13141, maxDocs=44421)
          0.125 = fieldNorm(doc=1402)
  0.25 = coord(1/4)

Source

Bibliothek: Forschung und Praxis. 14(1990), S.226-234