Search (284 results, page 2 of 15)

  • × theme_ss:"Retrievalalgorithmen"
  • × type_ss:"a"
  1. Reimer, U.: Empfehlungssysteme (2023) 0.01 
    0.011424865 = product of:
  0.034274593 = sum of:
    0.010820055 = weight(_text_:in in 519) [ClassicSimilarity], result of:
      0.010820055 = score(doc=519,freq=6.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.1822149 = fieldWeight in 519, product of:
          2.4494898 = tf(freq=6.0), with freq of:
            6.0 = termFreq=6.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.0546875 = fieldNorm(doc=519)
    0.023454536 = weight(_text_:und in 519) [ClassicSimilarity], result of:
      0.023454536 = score(doc=519,freq=4.0), product of:
        0.09675359 = queryWeight, product of:
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.043654136 = queryNorm
        0.24241515 = fieldWeight in 519, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.0546875 = fieldNorm(doc=519)
  0.33333334 = coord(2/6)
    Abstract
    Mit der wachsenden Informationsflut steigen die Anforderungen an Informationssysteme, aus der Menge potenziell relevanter Information die in einem bestimmten Kontext relevanteste zu selektieren. Empfehlungssysteme spielen hier eine besondere Rolle, da sie personalisiert - d. h. kontextspezifisch und benutzerindividuell - relevante Information herausfiltern können. Definition: Ein Empfehlungssystem empfiehlt einem Benutzer bzw. einer Benutzerin in einem definierten Kontext aus einer gegebenen Menge von Empfehlungsobjekten eine Teilmenge als relevant. Empfehlungssysteme machen Benutzer auf Objekte aufmerksam, die sie möglicherweise nie gefunden hätten, weil sie nicht danach gesucht hätten oder sie in der schieren Menge an insgesamt relevanter Information untergegangen wären.
    Source
    Grundlagen der Informationswissenschaft. Hrsg.: Rainer Kuhlen, Dirk Lewandowski, Wolfgang Semar und Christa Womser-Hacker. 7., völlig neu gefasste Ausg
  2. Bornmann, L.; Mutz, R.: From P100 to P100' : a new citation-rank approach (2014) 0.01 
    0.011251582 = product of:
  0.033754744 = sum of:
    0.010096614 = weight(_text_:in in 1431) [ClassicSimilarity], result of:
      0.010096614 = score(doc=1431,freq=4.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.17003182 = fieldWeight in 1431, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.0625 = fieldNorm(doc=1431)
    0.02365813 = product of:
      0.04731626 = sum of:
        0.04731626 = weight(_text_:22 in 1431) [ClassicSimilarity], result of:
          0.04731626 = score(doc=1431,freq=2.0), product of:
            0.15286934 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043654136 = queryNorm
            0.30952093 = fieldWeight in 1431, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0625 = fieldNorm(doc=1431)
      0.5 = coord(1/2)
  0.33333334 = coord(2/6)
    Abstract
    Properties of a percentile-based rating scale needed in bibliometrics are formulated. Based on these properties, P100 was recently introduced as a new citation-rank approach (Bornmann, Leydesdorff, & Wang, 2013). In this paper, we conceptualize P100 and propose an improvement which we call P100'. Advantages and disadvantages of citation-rank indicators are noted.
    Date
    22. 8.2014 17:05:18
  3. Fuhr, N.: Modelle im Information Retrieval (2023) 0.01 
    0.010933193 = product of:
  0.03279958 = sum of:
    0.006310384 = weight(_text_:in in 800) [ClassicSimilarity], result of:
      0.006310384 = score(doc=800,freq=4.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.10626988 = fieldWeight in 800, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.0390625 = fieldNorm(doc=800)
    0.026489196 = weight(_text_:und in 800) [ClassicSimilarity], result of:
      0.026489196 = score(doc=800,freq=10.0), product of:
        0.09675359 = queryWeight, product of:
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.043654136 = queryNorm
        0.27378 = fieldWeight in 800, product of:
          3.1622777 = tf(freq=10.0), with freq of:
            10.0 = termFreq=10.0
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.0390625 = fieldNorm(doc=800)
  0.33333334 = coord(2/6)
    Abstract
    Information-Retrieval-Modelle -(IR-Modelle) spezifizieren, wie zu einer gegebenen Anfrage die Antwortdokumente aus einer Dokumentenkollektion bestimmt werden. Ausgangsbasis jedes Modells sind dabei zunächst bestimmte Annahmen über die Wissensrepräsentation (s. Teil B Methoden und Systeme der Inhaltserschließung) von Fragen und Dokumenten. Hier bezeichnen wir die Elemente dieser Repräsentationen als Terme, wobei es aus der Sicht des Modells egal ist, wie diese Terme aus dem Dokument (und analog aus der von Benutzenden eingegebenen Anfrage) abgeleitet werden: Bei Texten werden hierzu häufig computerlinguistische Methoden eingesetzt, aber auch komplexere automatische oder manuelle Erschließungsverfahren können zur Anwendung kommen. Repräsentationen besitzen ferner eine bestimmte Struktur. Ein Dokument wird meist als Menge oder Multimenge von Termen aufgefasst, wobei im zweiten Fall das Mehrfachvorkommen berücksichtigt wird. Diese Dokumentrepräsentation wird wiederum auf eine sogenannte Dokumentbeschreibung abgebildet, in der die einzelnen Terme gewichtet sein können. Im Folgenden unterscheiden wir nur zwischen ungewichteter (Gewicht eines Terms ist entweder 0 oder 1) und gewichteter Indexierung (das Gewicht ist eine nichtnegative reelle Zahl). Analog dazu gibt es eine Fragerepräsentation; legt man eine natürlichsprachige Anfrage zugrunde, so kann man die o. g. Verfahren für Dokumenttexte anwenden. Alternativ werden auch grafische oder formale Anfragesprachen verwendet, wobei aus Sicht der Modelle insbesondere deren logische Struktur (etwa beim Booleschen Retrieval) relevant ist. Die Fragerepräsentation wird dann in eine Fragebeschreibung überführt.
    Source
    Grundlagen der Informationswissenschaft. Hrsg.: Rainer Kuhlen, Dirk Lewandowski, Wolfgang Semar und Christa Womser-Hacker. 7., völlig neu gefasste Ausg
  4. Ravana, S.D.; Rajagopal, P.; Balakrishnan, V.: Ranking retrieval systems using pseudo relevance judgments (2015) 0.01 
    0.010613645 = product of:
  0.031840935 = sum of:
    0.010929906 = weight(_text_:in in 2591) [ClassicSimilarity], result of:
      0.010929906 = score(doc=2591,freq=12.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.18406484 = fieldWeight in 2591, product of:
          3.4641016 = tf(freq=12.0), with freq of:
            12.0 = termFreq=12.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.0390625 = fieldNorm(doc=2591)
    0.02091103 = product of:
      0.04182206 = sum of:
        0.04182206 = weight(_text_:22 in 2591) [ClassicSimilarity], result of:
          0.04182206 = score(doc=2591,freq=4.0), product of:
            0.15286934 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043654136 = queryNorm
            0.27358043 = fieldWeight in 2591, product of:
              2.0 = tf(freq=4.0), with freq of:
                4.0 = termFreq=4.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0390625 = fieldNorm(doc=2591)
      0.5 = coord(1/2)
  0.33333334 = coord(2/6)
    Abstract
    Purpose In a system-based approach, replicating the web would require large test collections, and judging the relevancy of all documents per topic in creating relevance judgment through human assessors is infeasible. Due to the large amount of documents that requires judgment, there are possible errors introduced by human assessors because of disagreements. The paper aims to discuss these issues. Design/methodology/approach This study explores exponential variation and document ranking methods that generate a reliable set of relevance judgments (pseudo relevance judgments) to reduce human efforts. These methods overcome problems with large amounts of documents for judgment while avoiding human disagreement errors during the judgment process. This study utilizes two key factors: number of occurrences of each document per topic from all the system runs; and document rankings to generate the alternate methods. Findings The effectiveness of the proposed method is evaluated using the correlation coefficient of ranked systems using mean average precision scores between the original Text REtrieval Conference (TREC) relevance judgments and pseudo relevance judgments. The results suggest that the proposed document ranking method with a pool depth of 100 could be a reliable alternative to reduce human effort and disagreement errors involved in generating TREC-like relevance judgments. Originality/value Simple methods proposed in this study show improvement in the correlation coefficient in generating alternate relevance judgment without human assessors while contributing to information retrieval evaluation.
    Date
    20. 1.2015 18:30:22
    18. 9.2018 18:22:56
  5. Pfeifer, U.; Pennekamp, S.: Incremental processing of vague queries in interactive retrieval systems (1997) 0.01 
    0.010439968 = product of:
  0.0313199 = sum of:
    0.012365777 = weight(_text_:in in 735) [ClassicSimilarity], result of:
      0.012365777 = score(doc=735,freq=6.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.2082456 = fieldWeight in 735, product of:
          2.4494898 = tf(freq=6.0), with freq of:
            6.0 = termFreq=6.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.0625 = fieldNorm(doc=735)
    0.018954126 = weight(_text_:und in 735) [ClassicSimilarity], result of:
      0.018954126 = score(doc=735,freq=2.0), product of:
        0.09675359 = queryWeight, product of:
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.043654136 = queryNorm
        0.19590102 = fieldWeight in 735, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.0625 = fieldNorm(doc=735)
  0.33333334 = coord(2/6)
    Abstract
    The application of information retrieval techniques in interactive environments requires systems capable of effeciently processing vague queries. To reach reasonable response times, new data structures and algorithms have to be developed. In this paper we describe an approach taking advantage of the conditions of interactive usage and special access paths. To have a reference we investigate text queries and compared our algorithms to the well known 'Buckley/Lewit' algorithm. We achieved significant improvements for the response times
    Source
    Hypertext - Information Retrieval - Multimedia '97: Theorien, Modelle und Implementierungen integrierter elektronischer Informationssysteme. Proceedings HIM '97. Hrsg.: N. Fuhr u.a
  6. Maylein, L.; Langenstein, A.: Neues vom Relevanz-Ranking im HEIDI-Katalog der Universitätsbibliothek Heidelberg : Perspektiven für bibliothekarische Dienstleistungen (2013) 0.01 
    0.010439968 = product of:
  0.0313199 = sum of:
    0.012365777 = weight(_text_:in in 775) [ClassicSimilarity], result of:
      0.012365777 = score(doc=775,freq=6.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.2082456 = fieldWeight in 775, product of:
          2.4494898 = tf(freq=6.0), with freq of:
            6.0 = termFreq=6.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.0625 = fieldNorm(doc=775)
    0.018954126 = weight(_text_:und in 775) [ClassicSimilarity], result of:
      0.018954126 = score(doc=775,freq=2.0), product of:
        0.09675359 = queryWeight, product of:
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.043654136 = queryNorm
        0.19590102 = fieldWeight in 775, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.0625 = fieldNorm(doc=775)
  0.33333334 = coord(2/6)
    Abstract
    Das Relevanz-Ranking im Katalog der Universitätsbibliothek Heidelberg HEIDI, bereits 2009 in einem Beitrag in dieser Zeitschrift beschrieben, wurde in den letzten Jahren durch neue Entwicklungen und Methoden stark verbessert. Der Aufsatz beschreibt die Realisierung der bisherigen Rankingmaßnahmen unter der neu eingesetzten Suchmaschinenplattform SOLR. Weiter werden verschiedene neue Möglichkeiten für Rankinganpassungen unter SOLR sowie deren Einsatz im HEIDI-Katalog dargestellt.
  7. Oberhauser, O.: Relevance Ranking in den Online-Katalogen der "nächsten Generation" (2010) 0.01 
    0.010270989 = product of:
  0.030812964 = sum of:
    0.010709076 = weight(_text_:in in 4308) [ClassicSimilarity], result of:
      0.010709076 = score(doc=4308,freq=8.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.18034597 = fieldWeight in 4308, product of:
          2.828427 = tf(freq=8.0), with freq of:
            8.0 = termFreq=8.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.046875 = fieldNorm(doc=4308)
    0.020103889 = weight(_text_:und in 4308) [ClassicSimilarity], result of:
      0.020103889 = score(doc=4308,freq=4.0), product of:
        0.09675359 = queryWeight, product of:
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.043654136 = queryNorm
        0.20778441 = fieldWeight in 4308, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.046875 = fieldNorm(doc=4308)
  0.33333334 = coord(2/6)
    Abstract
    Relevance Ranking in Online-Katalogen ist zwar kein neues Thema, doch liegt dazu nicht allzu viel Literatur vor, die das Prädikat "ernstzunehmen" verdient. Dies ist zum einen darin begründet, dass das Interesse an der Ausgabe ranggereihter Ergebnislisten auf Seiten aller Beteiligter (Bibliothekare, Softwarehersteller, Benutzer) traditionell gering war. Zum anderen ging die seit einigen Jahren populär gewordene Kritik an den bestehenden OPACs vielfach von einer unzureichenden Wissensbasis aus und produzierte oft nur polemische oder emotional gefärbte Beiträge, die zum Thema Ranking wenig beitrugen. ... Der hier beschriebene Test ist natürlich in keiner Weise erschöpfend oder repräsentativ. Dennoch gibt er, wie ich glaube, Anlass zu einiger Hoffnung. Er lässt vermuten, dass die "neuen" OPACs - zumindest was das Relevance Ranking betrifft - auf dem Weg in die richtige Richtung sind. Wie gut es wirklich gelingen wird, die Rankingleistung von Suchmaschinen wie Google, die unter völlig anderen Voraussetzungen arbeiten, einzuholen, wird aber erst die Zukunft zeigen.
    Source
    Mitteilungen der Vereinigung Österreichischer Bibliothekarinnen und Bibliothekare. 63(2010) H.1/2, S.25-37
  8. Faloutsos, C.: Signature files (1992) 0.01 
    0.010265838 = product of:
  0.030797515 = sum of:
    0.0071393843 = weight(_text_:in in 3499) [ClassicSimilarity], result of:
      0.0071393843 = score(doc=3499,freq=2.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.120230645 = fieldWeight in 3499, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.0625 = fieldNorm(doc=3499)
    0.02365813 = product of:
      0.04731626 = sum of:
        0.04731626 = weight(_text_:22 in 3499) [ClassicSimilarity], result of:
          0.04731626 = score(doc=3499,freq=2.0), product of:
            0.15286934 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043654136 = queryNorm
            0.30952093 = fieldWeight in 3499, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0625 = fieldNorm(doc=3499)
      0.5 = coord(1/2)
  0.33333334 = coord(2/6)
    Abstract
    Presents a survey and discussion on signature-based text retrieval methods. It describes the main idea behind the signature approach and its advantages over other text retrieval methods, it provides a classification of the signature methods that have appeared in the literature, it describes the main representatives of each class, together with the relative advantages and drawbacks, and it gives a list of applications as well as commercial or university prototypes that use the signature approach
    Date
    7. 5.1999 15:22:48
  9. Losada, D.E.; Barreiro, A.: Emebedding term similarity and inverse document frequency into a logical model of information retrieval (2003) 0.01 
    0.010265838 = product of:
  0.030797515 = sum of:
    0.0071393843 = weight(_text_:in in 1422) [ClassicSimilarity], result of:
      0.0071393843 = score(doc=1422,freq=2.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.120230645 = fieldWeight in 1422, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.0625 = fieldNorm(doc=1422)
    0.02365813 = product of:
      0.04731626 = sum of:
        0.04731626 = weight(_text_:22 in 1422) [ClassicSimilarity], result of:
          0.04731626 = score(doc=1422,freq=2.0), product of:
            0.15286934 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043654136 = queryNorm
            0.30952093 = fieldWeight in 1422, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0625 = fieldNorm(doc=1422)
      0.5 = coord(1/2)
  0.33333334 = coord(2/6)
    Date
    22. 3.2003 19:27:23
    Footnote
    Beitrag eines Themenheftes: Mathematical, logical, and formal methods in information retrieval
  10. Witschel, H.F.: Global term weights in distributed environments (2008) 0.01 
    0.00990557 = product of:
  0.02971671 = sum of:
    0.011973113 = weight(_text_:in in 2096) [ClassicSimilarity], result of:
      0.011973113 = score(doc=2096,freq=10.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.20163295 = fieldWeight in 2096, product of:
          3.1622777 = tf(freq=10.0), with freq of:
            10.0 = termFreq=10.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.046875 = fieldNorm(doc=2096)
    0.017743597 = product of:
      0.035487194 = sum of:
        0.035487194 = weight(_text_:22 in 2096) [ClassicSimilarity], result of:
          0.035487194 = score(doc=2096,freq=2.0), product of:
            0.15286934 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043654136 = queryNorm
            0.23214069 = fieldWeight in 2096, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.046875 = fieldNorm(doc=2096)
      0.5 = coord(1/2)
  0.33333334 = coord(2/6)
    Abstract
    This paper examines the estimation of global term weights (such as IDF) in information retrieval scenarios where a global view on the collection is not available. In particular, the two options of either sampling documents or of using a reference corpus independent of the target retrieval collection are compared using standard IR test collections. In addition, the possibility of pruning term lists based on frequency is evaluated. The results show that very good retrieval performance can be reached when just the most frequent terms of a collection - an "extended stop word list" - are known and all terms which are not in that list are treated equally. However, the list cannot always be fully estimated from a general-purpose reference corpus, but some "domain-specific stop words" need to be added. A good solution for achieving this is to mix estimates from small samples of the target retrieval collection with ones derived from a reference corpus.
    Date
    1. 8.2008 9:44:22
  11. Klas, C.-P.; Fuhr, N.; Schaefer, A.: Evaluating strategic support for information access in the DAFFODIL system (2004) 0.01 
    0.00990557 = product of:
  0.02971671 = sum of:
    0.011973113 = weight(_text_:in in 2419) [ClassicSimilarity], result of:
      0.011973113 = score(doc=2419,freq=10.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.20163295 = fieldWeight in 2419, product of:
          3.1622777 = tf(freq=10.0), with freq of:
            10.0 = termFreq=10.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.046875 = fieldNorm(doc=2419)
    0.017743597 = product of:
      0.035487194 = sum of:
        0.035487194 = weight(_text_:22 in 2419) [ClassicSimilarity], result of:
          0.035487194 = score(doc=2419,freq=2.0), product of:
            0.15286934 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043654136 = queryNorm
            0.23214069 = fieldWeight in 2419, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.046875 = fieldNorm(doc=2419)
      0.5 = coord(1/2)
  0.33333334 = coord(2/6)
    Abstract
    The digital library system Daffodil is targeted at strategic support of users during the information search process. For searching, exploring and managing digital library objects it provides user-customisable information seeking patterns over a federation of heterogeneous digital libraries. In this paper evaluation results with respect to retrieval effectiveness, efficiency and user satisfaction are presented. The analysis focuses on strategic support for the scientific work-flow. Daffodil supports the whole work-flow, from data source selection over information seeking to the representation, organisation and reuse of information. By embedding high level search functionality into the scientific work-flow, the user experiences better strategic system support due to a more systematic work process. These ideas have been implemented in Daffodil followed by a qualitative evaluation. The evaluation has been conducted with 28 participants, ranging from information seeking novices to experts. The results are promising, as they support the chosen model.
    Date
    16.11.2008 16:22:48
    Series
    Lecture notes in computer science; vol.3232
    Theme
    Semantisches Umfeld in Indexierung u. Retrieval
  12. Campos, L.M. de; Fernández-Luna, J.M.; Huete, J.F.: Implementing relevance feedback in the Bayesian network retrieval model (2003) 0.01 
    0.00990557 = product of:
  0.02971671 = sum of:
    0.011973113 = weight(_text_:in in 825) [ClassicSimilarity], result of:
      0.011973113 = score(doc=825,freq=10.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.20163295 = fieldWeight in 825, product of:
          3.1622777 = tf(freq=10.0), with freq of:
            10.0 = termFreq=10.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.046875 = fieldNorm(doc=825)
    0.017743597 = product of:
      0.035487194 = sum of:
        0.035487194 = weight(_text_:22 in 825) [ClassicSimilarity], result of:
          0.035487194 = score(doc=825,freq=2.0), product of:
            0.15286934 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043654136 = queryNorm
            0.23214069 = fieldWeight in 825, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.046875 = fieldNorm(doc=825)
      0.5 = coord(1/2)
  0.33333334 = coord(2/6)
    Abstract
    Relevance Feedback consists in automatically formulating a new query according to the relevance judgments provided by the user after evaluating a set of retrieved documents. In this article, we introduce several relevance feedback methods for the Bayesian Network Retrieval ModeL The theoretical frame an which our methods are based uses the concept of partial evidences, which summarize the new pieces of information gathered after evaluating the results obtained by the original query. These partial evidences are inserted into the underlying Bayesian network and a new inference process (probabilities propagation) is run to compute the posterior relevance probabilities of the documents in the collection given the new query. The quality of the proposed methods is tested using a preliminary experimentation with different standard document collections.
    Date
    22. 3.2003 19:30:19
    Footnote
    Beitrag eines Themenheftes: Mathematical, logical, and formal methods in information retrieval
  13. Crestani, F.; Dominich, S.; Lalmas, M.; Rijsbergen, C.J.K. van: Mathematical, logical, and formal methods in information retrieval : an introduction to the special issue (2003) 0.01 
    0.009484224 = product of:
  0.028452672 = sum of:
    0.010709076 = weight(_text_:in in 1451) [ClassicSimilarity], result of:
      0.010709076 = score(doc=1451,freq=8.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.18034597 = fieldWeight in 1451, product of:
          2.828427 = tf(freq=8.0), with freq of:
            8.0 = termFreq=8.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.046875 = fieldNorm(doc=1451)
    0.017743597 = product of:
      0.035487194 = sum of:
        0.035487194 = weight(_text_:22 in 1451) [ClassicSimilarity], result of:
          0.035487194 = score(doc=1451,freq=2.0), product of:
            0.15286934 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043654136 = queryNorm
            0.23214069 = fieldWeight in 1451, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.046875 = fieldNorm(doc=1451)
      0.5 = coord(1/2)
  0.33333334 = coord(2/6)
    Abstract
    Research an the use of mathematical, logical, and formal methods, has been central to Information Retrieval research for a long time. Research in this area is important not only because it helps enhancing retrieval effectiveness, but also because it helps clarifying the underlying concepts of Information Retrieval. In this article we outline some of the major aspects of the subject, and summarize the papers of this special issue with respect to how they relate to these aspects. We conclude by highlighting some directions of future research, which are needed to better understand the formal characteristics of Information Retrieval.
    Date
    22. 3.2003 19:27:36
    Footnote
    Einführung zu den Beiträgen eines Themenheftes: Mathematical, logical, and formal methods in information retrieval
  14. Fan, W.; Fox, E.A.; Pathak, P.; Wu, H.: ¬The effects of fitness functions an genetic programming-based ranking discovery for Web search (2004) 0.01 
    0.009484224 = product of:
  0.028452672 = sum of:
    0.010709076 = weight(_text_:in in 2239) [ClassicSimilarity], result of:
      0.010709076 = score(doc=2239,freq=8.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.18034597 = fieldWeight in 2239, product of:
          2.828427 = tf(freq=8.0), with freq of:
            8.0 = termFreq=8.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.046875 = fieldNorm(doc=2239)
    0.017743597 = product of:
      0.035487194 = sum of:
        0.035487194 = weight(_text_:22 in 2239) [ClassicSimilarity], result of:
          0.035487194 = score(doc=2239,freq=2.0), product of:
            0.15286934 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043654136 = queryNorm
            0.23214069 = fieldWeight in 2239, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.046875 = fieldNorm(doc=2239)
      0.5 = coord(1/2)
  0.33333334 = coord(2/6)
    Abstract
    Genetic-based evolutionary learning algorithms, such as genetic algorithms (GAs) and genetic programming (GP), have been applied to information retrieval (IR) since the 1980s. Recently, GP has been applied to a new IR taskdiscovery of ranking functions for Web search-and has achieved very promising results. However, in our prior research, only one fitness function has been used for GP-based learning. It is unclear how other fitness functions may affect ranking function discovery for Web search, especially since it is weIl known that choosing a proper fitness function is very important for the effectiveness and efficiency of evolutionary algorithms. In this article, we report our experience in contrasting different fitness function designs an GP-based learning using a very large Web corpus. Our results indicate that the design of fitness functions is instrumental in performance improvement. We also give recommendations an the design of fitness functions for genetic-based information retrieval experiments.
    Date
    31. 5.2004 19:22:06
  15. Furner, J.: ¬A unifying model of document relatedness for hybrid search engines (2003) 0.01 
    0.009484224 = product of:
  0.028452672 = sum of:
    0.010709076 = weight(_text_:in in 2717) [ClassicSimilarity], result of:
      0.010709076 = score(doc=2717,freq=8.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.18034597 = fieldWeight in 2717, product of:
          2.828427 = tf(freq=8.0), with freq of:
            8.0 = termFreq=8.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.046875 = fieldNorm(doc=2717)
    0.017743597 = product of:
      0.035487194 = sum of:
        0.035487194 = weight(_text_:22 in 2717) [ClassicSimilarity], result of:
          0.035487194 = score(doc=2717,freq=2.0), product of:
            0.15286934 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043654136 = queryNorm
            0.23214069 = fieldWeight in 2717, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.046875 = fieldNorm(doc=2717)
      0.5 = coord(1/2)
  0.33333334 = coord(2/6)
    Abstract
    Previous work an search-engine design has indicated that information-seekers may benefit from being given the opportunity to exploit multiple sources of evidence of document relatedness. Few existing systems, however, give users more than minimal control over the selections that may be made among methods of exploitation. By applying the methods of "document network analysis" (DNA), a unifying, graph-theoretic model of content-, collaboration-, and context-based systems (CCC) may be developed in which the nature of the similarities between types of document relatedness and document ranking are clarified. The usefulness of the approach to system design suggested by this model may be tested by constructing and evaluating a prototype system (UCXtra) that allows searchers to maintain control over the multiple ways in which document collections may be ranked and re-ranked.
    Date
    11. 9.2004 17:32:22
    Series
    Advances in knowledge organization; vol.8
    Source
    Challenges in knowledge representation and organization for the 21st century: Integration of knowledge across boundaries. Proceedings of the 7th ISKO International Conference Granada, Spain, July 10-13, 2002. Ed.: M. López-Huertas
  16. Lanvent, A.: Licht im Daten Chaos (2004) 0.01 
    0.009443581 = product of:
  0.028330743 = sum of:
    0.0071393843 = weight(_text_:in in 2806) [ClassicSimilarity], result of:
      0.0071393843 = score(doc=2806,freq=8.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.120230645 = fieldWeight in 2806, product of:
          2.828427 = tf(freq=8.0), with freq of:
            8.0 = termFreq=8.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.03125 = fieldNorm(doc=2806)
    0.021191359 = weight(_text_:und in 2806) [ClassicSimilarity], result of:
      0.021191359 = score(doc=2806,freq=10.0), product of:
        0.09675359 = queryWeight, product of:
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.043654136 = queryNorm
        0.219024 = fieldWeight in 2806, product of:
          3.1622777 = tf(freq=10.0), with freq of:
            10.0 = termFreq=10.0
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.03125 = fieldNorm(doc=2806)
  0.33333334 = coord(2/6)
    Content
    "Bitte suchen Sie alle Unterlagen, die im PC zum Ibelshäuser-Vertrag in Sprockhövel gespeichert sind. Finden Sie alles, was wir haben - Dokumente, Tabellen, Präsentationen, Scans, E-Mails. Und erledigen Sie das gleich! « Wer diese Aufgabe an das Windows-eigene Suchmodul vergibt, wird zwangsläufig enttäuscht. Denn das Betriebssystem beherrscht weder die formatübergreifende Recherche noch die Kontextsuche, die für solche komplexen Aufträge nötig sind. Professionelle Desktop-Suchmaschinen erledigen Aufgaben dieser Art jedoch im Handumdrehen - genauer gesagt in einer einzigen Sekunde. Spitzenprogramme wie Global Brain benötigen dafür nicht einmal umfangreiche Abfrageformulare. Es genügt, einen Satz im Eingabefeld zu formulieren, der das Thema der gewünschten Dokumente eingrenzt. Dabei suchen die Programme über alle Laufwerke, die sich auf dem System einbinden lassen - also auch im Netzwerk-Ordner (Shared Folder), sofern dieser freigegeben wurde. Allen Testkandidaten - mit Ausnahme von Search 32 - gemeinsam ist, dass sie weitaus bessere Rechercheergebnisse abliefern als Windows, deutlich schneller arbeiten und meist auch in den Online-Postfächern stöbern. Wer schon öfter vergeblich über die Windows-Suche nach wichtigen Dokumenten gefahndet hat, kommt angesichts der Qualität der Search-Engines kaum mehr um die Anschaffung eines Desktop-Suchtools herum. Aber Microsoft will nachbessern. Für den Windows-XP-Nachfolger Longhorn wirbt der Hersteller vor allem mit dem Hinweis auf das neue Dateisystem WinFS, das sämtliche Files auf der Festplatte über Meta-Tags indiziert und dem Anwender damit lange Suchläufe erspart. So sollen sich anders als bei Windows XP alle Dateien zu bestimmten Themen in wenigen Sekunden auflisten lassen - unabhängig vom Format und vom physikalischen Speicherort der Files. Für die Recherche selbst ist dann weder der Dateiname noch das Erstelldatum ausschlaggebend. Anhand der kontextsensitiven Suche von WinFS kann der Anwender einfach einen Suchbefehl wie »Vertragsabschluss mit Firma XYZ, Neunkirchen/Saar« eingeben, der dann ohne Umwege zum Ziel führt."
    Footnote
    Darin auch 2 Teilbeiträge: (1) Know-how - Suchverfahren; (2) Praxis - Windows-Suche und Indexdienst
  17. Efthimiadis, E.N.: User choices : a new yardstick for the evaluation of ranking algorithms for interactive query expansion (1995) 0.01 
    0.0091357 = product of:
  0.027407099 = sum of:
    0.012620768 = weight(_text_:in in 5697) [ClassicSimilarity], result of:
      0.012620768 = score(doc=5697,freq=16.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.21253976 = fieldWeight in 5697, product of:
          4.0 = tf(freq=16.0), with freq of:
            16.0 = termFreq=16.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.0390625 = fieldNorm(doc=5697)
    0.014786332 = product of:
      0.029572664 = sum of:
        0.029572664 = weight(_text_:22 in 5697) [ClassicSimilarity], result of:
          0.029572664 = score(doc=5697,freq=2.0), product of:
            0.15286934 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043654136 = queryNorm
            0.19345059 = fieldWeight in 5697, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0390625 = fieldNorm(doc=5697)
      0.5 = coord(1/2)
  0.33333334 = coord(2/6)
    Abstract
    The performance of 8 ranking algorithms was evaluated with respect to their effectiveness in ranking terms for query expansion. The evaluation was conducted within an investigation of interactive query expansion and relevance feedback in a real operational environment. Focuses on the identification of algorithms that most effectively take cognizance of user preferences. user choices (i.e. the terms selected by the searchers for the query expansion search) provided the yardstick for the evaluation of the 8 ranking algorithms. This methodology introduces a user oriented approach in evaluating ranking algorithms for query expansion in contrast to the standard, system oriented approaches. Similarities in the performance of the 8 algorithms and the ways these algorithms rank terms were the main focus of this evaluation. The findings demonstrate that the r-lohi, wpq, enim, and porter algorithms have similar performance in bringing good terms to the top of a ranked list of terms for query expansion. However, further evaluation of the algorithms in different (e.g. full text) environments is needed before these results can be generalized beyond the context of the present study
    Date
    22. 2.1996 13:14:10
    Theme
    Semantisches Umfeld in Indexierung u. Retrieval
  18. Chang, C.-H.; Hsu, C.-C.: Integrating query expansion and conceptual relevance feedback for personalized Web information retrieval (1998) 0.01 
    0.008982609 = product of:
  0.026947826 = sum of:
    0.006246961 = weight(_text_:in in 1319) [ClassicSimilarity], result of:
      0.006246961 = score(doc=1319,freq=2.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.10520181 = fieldWeight in 1319, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.0546875 = fieldNorm(doc=1319)
    0.020700864 = product of:
      0.04140173 = sum of:
        0.04140173 = weight(_text_:22 in 1319) [ClassicSimilarity], result of:
          0.04140173 = score(doc=1319,freq=2.0), product of:
            0.15286934 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043654136 = queryNorm
            0.2708308 = fieldWeight in 1319, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0546875 = fieldNorm(doc=1319)
      0.5 = coord(1/2)
  0.33333334 = coord(2/6)
    Date
    1. 8.1996 22:08:06
    Theme
    Semantisches Umfeld in Indexierung u. Retrieval
  19. Kleinberg, J.M.: Authoritative sources in a hyperlinked environment (1998) 0.01 
    0.00872957 = product of:
  0.026188709 = sum of:
    0.011973113 = weight(_text_:in in 5) [ClassicSimilarity], result of:
      0.011973113 = score(doc=5,freq=10.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.20163295 = fieldWeight in 5, product of:
          3.1622777 = tf(freq=10.0), with freq of:
            10.0 = termFreq=10.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.046875 = fieldNorm(doc=5)
    0.014215595 = weight(_text_:und in 5) [ClassicSimilarity], result of:
      0.014215595 = score(doc=5,freq=2.0), product of:
        0.09675359 = queryWeight, product of:
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.043654136 = queryNorm
        0.14692576 = fieldWeight in 5, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.046875 = fieldNorm(doc=5)
  0.33333334 = coord(2/6)
    Abstract
    The network structure of a hyperlinked environment can be a rich source of information about the content of the environment, provided we have effective means for understanding it. We develop a set of algorithmic tools for extracting information from the link structures of such environments, and report on experiments that demonstrate their effectiveness in a variety of contexts on the World Wide Web. The central issue we address within our framework is the distillation of broad search topics, through the discovery of "authoritative" information sources on such topics. We propose and test an algorithmic formulation of the notion of authority, based on the relationship between a set of relevant authoritative pages and the set of "hub pages" that join them together in the link structure. Our formulation has connections to the eigenvectors of certain matrices associated with the link graph; these connections in turn motivate additional heuristics for link-based analysis.
    Content
    Vorversionen auch in: Proceedings of the ACM-SIAM Symposium on Discrete Algorithms, 1998, und als IBM Research Report RJ 10076, May 1997.
  20. Chakrabarti, S.; Dom, B.; Kumar, S.R.; Raghavan, P.; Rajagopalan, S.; Tomkins, A.; Kleinberg, J.M.; Gibson, D.: Neue Pfade durch den Internet-Dschungel : Die zweite Generation von Web-Suchmaschinen (1999) 0.01 
    0.008697838 = product of:
  0.02609351 = sum of:
    0.0071393843 = weight(_text_:in in 3) [ClassicSimilarity], result of:
      0.0071393843 = score(doc=3,freq=2.0), product of:
        0.059380736 = queryWeight, product of:
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.043654136 = queryNorm
        0.120230645 = fieldWeight in 3, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.3602545 = idf(docFreq=30841, maxDocs=44218)
          0.0625 = fieldNorm(doc=3)
    0.018954126 = weight(_text_:und in 3) [ClassicSimilarity], result of:
      0.018954126 = score(doc=3,freq=2.0), product of:
        0.09675359 = queryWeight, product of:
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.043654136 = queryNorm
        0.19590102 = fieldWeight in 3, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          2.216367 = idf(docFreq=13101, maxDocs=44218)
          0.0625 = fieldNorm(doc=3)
  0.33333334 = coord(2/6)
    Abstract
    Die im WWW verfügbare Datenmenge wächst mit atemberaubender Geschwindigkeit; entsprechend schwieriger wird es, relevante Informationen zu finden. ein neues Analyseverfahren stellt nahezu automatische Abhilfe in Aussicht
    Content
    Ausnutzen der Hyperlinks für verbesserte Such- und Findeverfahren; Darstellung des HITS-Algorithmus

Authors

Years

Languages

  • e 251
  • d 30
  • chi 2
  • sp 1
  • More… Less…

Themes