Search (35 results, page 1 of 2)

  • × theme_ss:"Informetrie"
  • × year_i:[2000 TO 2010}
  1. Mayr, P.: Re-Ranking auf Basis von Bradfordizing für die verteilte Suche in Digitalen Bibliotheken (2009) 0.03
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    Abstract
    Trotz großer Dokumentmengen für datenbankübergreifende Literaturrecherchen erwarten akademische Nutzer einen möglichst hohen Anteil an relevanten und qualitativen Dokumenten in den Trefferergebnissen. Insbesondere die Reihenfolge und Struktur der gelisteten Ergebnisse (Ranking) spielt, neben dem direkten Volltextzugriff auf die Dokumente, inzwischen eine entscheidende Rolle beim Design von Suchsystemen. Nutzer erwarten weiterhin flexible Informationssysteme, die es unter anderem zulassen, Einfluss auf das Ranking der Dokumente zu nehmen bzw. alternative Rankingverfahren zu verwenden. In dieser Arbeit werden zwei Mehrwertverfahren für Suchsysteme vorgestellt, die die typischen Probleme bei der Recherche nach wissenschaftlicher Literatur behandeln und damit die Recherchesituation messbar verbessern können. Die beiden Mehrwertdienste semantische Heterogenitätsbehandlung am Beispiel Crosskonkordanzen und Re-Ranking auf Basis von Bradfordizing, die in unterschiedlichen Phasen der Suche zum Einsatz kommen, werden hier ausführlich beschrieben und im empirischen Teil der Arbeit bzgl. der Effektivität für typische fachbezogene Recherchen evaluiert. Vorrangiges Ziel der Promotion ist es, zu untersuchen, ob das hier vorgestellte alternative Re-Rankingverfahren Bradfordizing im Anwendungsbereich bibliographischer Datenbanken zum einen operabel ist und zum anderen voraussichtlich gewinnbringend in Informationssystemen eingesetzt und dem Nutzer angeboten werden kann. Für die Tests wurden Fragestellungen und Daten aus zwei Evaluationsprojekten (CLEF und KoMoHe) verwendet. Die intellektuell bewerteten Dokumente stammen aus insgesamt sieben wissenschaftlichen Fachdatenbanken der Fächer Sozialwissenschaften, Politikwissenschaft, Wirtschaftswissenschaften, Psychologie und Medizin. Die Evaluation der Crosskonkordanzen (insgesamt 82 Fragestellungen) zeigt, dass sich die Retrievalergebnisse signifikant für alle Crosskonkordanzen verbessern; es zeigt sich zudem, dass interdisziplinäre Crosskonkordanzen den stärksten (positiven) Effekt auf die Suchergebnisse haben. Die Evaluation des Re-Ranking nach Bradfordizing (insgesamt 164 Fragestellungen) zeigt, dass die Dokumente der Kernzone (Kernzeitschriften) für die meisten Testreihen eine signifikant höhere Precision als Dokumente der Zone 2 und Zone 3 (Peripheriezeitschriften) ergeben. Sowohl für Zeitschriften als auch für Monographien kann dieser Relevanzvorteil nach Bradfordizing auf einer sehr breiten Basis von Themen und Fragestellungen an zwei unabhängigen Dokumentkorpora empirisch nachgewiesen werden.
  2. Nicolaisen, J.: Citation analysis (2007) 0.03
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    Date
    13. 7.2008 19:53:22
  3. Van der Veer Martens, B.: Do citation systems represent theories of truth? (2001) 0.02
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    Date
    22. 7.2006 15:22:28
  4. fwt: Webseiten liegen im Schnitt nur 19 Klicks auseinander (2001) 0.02
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    Abstract
    "Dokumente im World Wide Web liegen durchschnittlich 19 Mausklicks voneinander entfernt - angesichts von schätzungsweise mehr als einer Milliarde Seiten erstaunlich nahe. Albert-Lazlo Barabai vom Institut für Physik der University von Notre Dame (US-Staat Indiana) stellt seine Studie in der britischen Fachzeitschrift Physics World (Juli 2001, S. 33) vor. Der Statistiker konstruierte im Rechner zunächst Modelle von großen Computernetzwerken. Grundlage für diese Abbilder war die Analyse eines kleinen Teils der Verbindungen im Web, die der Wissenschaftler automatisch von einem Programm hatte prüfen lassen. Um seine Ergebnisse zu erklären, vergleicht Barabai das World Wide Web mit den Verbindungen internationaler Fluglinien. Dort gebe es zahlreiche Flughäfen, die meist nur mit anderen Flugplätzen in ihrer näheren Umgebung in Verbindung stünden. Diese kleineren Verteiler stehen ihrerseits mit einigen wenigen großen Airports wie Frankfurt, New York oder Hongkong in Verbindung. Ähnlich sei es im Netz, wo wenige große Server die Verteilung großer Datenmengen übernähmen und weite Entfernungen überbrückten. Damit seien die Online-Wege vergleichsweise kurz. Die Untersuchung spiegelt allerdings die Situation des Jahres 1999 wider. Seinerzeit gab es vermutlich 800 Millionen Knoten."
  5. Lewison, G.: ¬The work of the Bibliometrics Research Group (City University) and associates (2005) 0.02
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    Date
    20. 1.2007 17:02:22
  6. Oberhauser, O.: Fachspezifische Suche nach elektronischen Zeitschriften : Ein webliographischer Streifzug am Beispiel der Informationswissenschaft (2003) 0.02
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    Form
    Elektronische Dokumente
  7. Raan, A.F.J. van: Statistical properties of bibliometric indicators : research group indicator distributions and correlations (2006) 0.01
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    Date
    22. 7.2006 16:20:22
  8. Larivière, V.; Gingras, Y.; Archambault, E.: ¬The decline in the concentration of citations, 1900-2007 (2009) 0.01
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    Date
    22. 3.2009 19:22:35
  9. Thelwall, M.; Ruschenburg, T.: Grundlagen und Forschungsfelder der Webometrie (2006) 0.01
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    Date
    4.12.2006 12:12:22
  10. Rostaing, H.; Barts, N.; Léveillé, V.: Bibliometrics: representation instrument of the multidisciplinary positioning of a scientific area : Implementation for an Advisory Scientific Committee (2007) 0.01
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    Date
    30.12.2007 11:22:39
  11. Levitt, J.M.; Thelwall, M.: Citation levels and collaboration within library and information science (2009) 0.01
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    Abstract
    Collaboration is a major research policy objective, but does it deliver higher quality research? This study uses citation analysis to examine the Web of Science (WoS) Information Science & Library Science subject category (IS&LS) to ascertain whether, in general, more highly cited articles are more highly collaborative than other articles. It consists of two investigations. The first investigation is a longitudinal comparison of the degree and proportion of collaboration in five strata of citation; it found that collaboration in the highest four citation strata (all in the most highly cited 22%) increased in unison over time, whereas collaboration in the lowest citation strata (un-cited articles) remained low and stable. Given that over 40% of the articles were un-cited, it seems important to take into account the differences found between un-cited articles and relatively highly cited articles when investigating collaboration in IS&LS. The second investigation compares collaboration for 35 influential information scientists; it found that their more highly cited articles on average were not more highly collaborative than their less highly cited articles. In summary, although collaborative research is conducive to high citation in general, collaboration has apparently not tended to be essential to the success of current and former elite information scientists.
    Date
    22. 3.2009 12:43:51
  12. Burrell, Q.L.: Predicting future citation behavior (2003) 0.01
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    Date
    29. 3.2003 19:22:48
  13. Leydesdorff, L.: Can networks of journal-journal citations be used as indicators of change in the social sciences? (2003) 0.01
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    Date
    6.11.2005 19:02:22
  14. Asonuma, A.; Fang, Y.; Rousseau, R.: Reflections on the age distribution of Japanese scientists (2006) 0.01
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    Date
    22. 7.2006 15:26:24
  15. Haycock, L.A.: Citation analysis of education dissertations for collection development (2004) 0.01
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    Date
    10. 9.2000 17:38:22
  16. Chan, H.C.; Kim, H.-W.; Tan, W.C.: Information systems citation patterns from International Conference on Information Systems articles (2006) 0.01
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    Date
    3. 1.2007 17:22:03
  17. H-Index auch im Web of Science (2008) 0.01
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    Date
    6. 4.2008 19:04:22
  18. Mingers, J.; Burrell, Q.L.: Modeling citation behavior in Management Science journals (2006) 0.01
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    Date
    26.12.2007 19:22:05
  19. Althouse, B.M.; West, J.D.; Bergstrom, C.T.; Bergstrom, T.: Differences in impact factor across fields and over time (2009) 0.01
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    Date
    23. 2.2009 18:22:28
  20. Zhang, Y.; Jansen, B.J.; Spink, A.: Identification of factors predicting clickthrough in Web searching using neural network analysis (2009) 0.01
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    Date
    22. 3.2009 17:49:11