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  • × author_ss:"Lewandowski, D."
  1. Lewandowski, D.: Alles nur noch Google? : Entwicklungen im Bereich der WWW-Suchmaschinen (2002) 0.01
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    Date
    29. 9.2002 18:49:22
  2. Lewandowski, D.: Abfragesprachen und erweiterte Funktionen von WWW-Suchmaschinen (2004) 0.01
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    Date
    28.11.2004 13:11:22
  3. Lewandowski, D.: Query understanding (2011) 0.01
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    Date
    18. 9.2018 18:22:18
  4. Lewandowski, D.: ¬Die Macht der Suchmaschinen und ihr Einfluss auf unsere Entscheidungen (2014) 0.01
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    Date
    22. 9.2014 18:54:11
  5. Lewandowski, D.; Sünkler, S.; Kerkmann, F.: Are ads on Google search engine results pages labeled clearly enough? : the influence of knowledge on search ads on users' selection behaviour (2017) 0.01
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    Abstract
    In an online experiment using a representative sample of the German online population (n = 1.000), we compare users' selection behaviour on two versions of the same Google search engine results page (SERP), one showing advertisements and organic results, the other showing organic results only. Selection behaviour is analyzed in relation to users' knowledge on Google's business model, on SERP design, and on these users' actual performance in marking advertisements on SERPs correctly. We find that users who were not able to mark ads correctly selected ads significantly more often. This leads to the conclusion that ads need to be labeled more clearly, and that there is a need for more information literacy in search engine users.
  6. Lewandowski, D.; Spree, U.: Ranking of Wikipedia articles in search engines revisited : fair ranking for reasonable quality? (2011) 0.01
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    Date
    30. 9.2012 19:27:22
  7. Lewandowski, D.; Sünkler, S.: What does Google recommend when you want to compare insurance offerings? (2019) 0.01
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    Date
    20. 1.2015 18:30:22
  8. Lewandowski, D.: Mit welchen Kennzahlen lässt sich die Qualität von Suchmaschinen messen? (2007) 0.01
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    Abstract
    Suchmaschinen bilden den bedeutendsten Zugang zu den im World Wide Web verfügbaren Informationen und haben andere Zugänge zu diesem Informationsbestand (wie etwa Internetverzeichnisse) weitgehend verdrängt. Der Suchmaschinenmarkt ist stark konzentriert; nur wenige Anbieter mit eigener Technologie bieten selbst Endnutzerlösungen an und lizenzieren ihre Technologie an die bekannten Web-Portale wie AOL oder T-Online. Die im vorliegenden Kapitel dargestellten Kennzahlen zur Messung der Qualität von Suchmaschinen basieren einerseits auf Erkenntnissen über den State of the Art der Suchmaschinentechnologie, andererseits stehen sie im Kontext eines umfassenderen Modells der Qualitätsmessung für Web-Suchmaschinen. Die besondere Bedeutung von Erkenntnissen über die Qualität der bestehenden Suchmaschinen ergibt sich einerseits aus ihrer Bedeutung für die Weiterentwicklung der Suchmaschinentechnologie. Qualitätsuntersuchungen geben Hinweise auf die Schwachstellen der Suchmaschinen im Allgemeinen und die ihrer Ranking-Algorithmen im Besonderen. Letztere sind als zentral für die Ergebnisqualität anzusehen und bilden den >Kern< der technologischen Leistungsfähigkeit einer jeden Suchmaschine.
  9. Lewandowski, D.: Suchmaschinen verstehen (2018) 0.01
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    Abstract
    Suchmaschinen sind heute die wichtigsten Werkzeuge, um an Informationen zu gelangen. Wir verwenden Suchmaschinen täglich, meist ohne weiter darüber nachzudenken. Doch wie funktionieren diese Suchwerkzeuge eigentlich genau? Das Buch betrachtet Suchmaschinen aus vier Perspektiven: Technik, Nutzung, Recherche und gesellschaftliche Bedeutung. Es bietet eine klar strukturierte und verständliche Einführung in die Thematik. Zahlreiche Abbildungen erlauben eine schnelle Erfassung des Stoffs. Neben einer ausführlichen Darstellung der in den bekannten Suchmaschinen verwendeten Rankingverfahren wird auch ausführlich auf das Nutzerverhalten eingegangen, das wiederum die Ergebnisdarstellung prägt. Dazu kommen grundlegende Betrachtungen des Suchmaschinenmarktes, der Bedeutung der Suchmaschinenoptimierung und der Rolle der Suchmaschinen als technische Informationsvermittler. Das Buch richtet sich an alle, die mit Suchmaschinen zu tun haben und ein umfassendes Verständnis dieser Suchwerkzeuge erlangen wollen, u.a. Suchmaschinenoptimierer, Entwickler, Informationswissenschaftler, Bibliothekare, Rechercheure in Wissenschaft und Praxis sowie Online-Marketing-Verantwortliche. Für die zweite Auflage wurde der Text vollständig überarbeitet. Neben einem neuen Kapitel zur Suchmaschinenwerbung wurden zahlreiche Abschnitte zu neu aufgekommenen Themen hinzugefügt. Alle Statistiken und Quellen wurden auf den neuesten Stand gebracht.
  10. Lewandowski, D.; Sünkler, S.; Hanisch, F.: Anzeigenkennzeichnung auf Suchergebnisseiten : Empirische Ergebnisse und Implikationen für die Forschung (2019) 0.01
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    Abstract
    In diesem Aufsatz stellen wir eine repräsentative Multimethodenstudie (bestehend aus Umfrage, aufgabenbasierter Nutzerstudie und OnlineExperiment) zum Wissen und Verhalten der deutschen Internetnutzer bezüglich der Anzeigen auf Google-Suchergebnisseiten vor. Die Ergebnisse zeigen, dass die überwiegende Mehrzahl der Nutzenden nicht hinreichend in der Lage ist, Werbung von organischen Ergebnissen zu unterscheiden. Die aufgabenbasierte Studie zeigt, dass lediglich 1,3 Prozent der Teilnehmenden alle Anzeigen und organischen Ergebnisse richtig markieren konnten. 9,6 Prozent haben ausschließlich korrekte Markierungen vorgenommen, dabei aber keine Vollständigkeit erreicht. Aus den Ergebnissen der Umfrage geht hervor, dass es viele Unklarheiten gibt über das Geschäftsmodell von Google und die Art und Weise, wie Suchmaschinenwerbung funktioniert. Die Ergebnisse des Online-Experiments zeigen, dass Nutzende, die die Unterscheidung zwischen Anzeigen und organischen Ergebnissen nicht verstehen, etwa doppelt so häufig auf Anzeigen klicken wie diejenigen, die diese Unterscheidung verstehen. Implikationen für die Forschung ergeben sich in den Bereichen Wiederholungsstudien bzw. Monitoring der Anzeigendarstellung, vertiefende Laborstudien, Modelle des Informationsverhaltens, Informationskompetenz und Entwicklung fairer Suchmaschinen.
  11. Lewandowski, D.: How can library materials be ranked in the OPAC? (2009) 0.01
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    Abstract
    Some Online Public Access Catalogues offer a ranking component. However, ranking there is merely text-based and is doomed to fail due to limited text in bibliographic data. The main assumption for the talk is that we are in a situation where the appropriate ranking factors for OPACs should be defined, while the implementation is no major problem. We must define what we want, and not so much focus on the technical work. Some deep thinking is necessary on the "perfect results set" and how we can achieve it through ranking. The talk presents a set of potential ranking factors and clustering possibilities for further discussion. A look at commercial Web search engines could provide us with ideas how ranking can be improved with additional factors. Search engines are way beyond pure text-based ranking and apply ranking factors in the groups like popularity, freshness, personalisation, etc. The talk describes the main factors used in search engines and how derivatives of these could be used for libraries' purposes. The goal of ranking is to provide the user with the best-suitable results on top of the results list. How can this goal be achieved with the library catalogue and also concerning the library's different collections and databases? The assumption is that ranking of such materials is a complex problem and is yet nowhere near solved. Libraries should focus on ranking to improve user experience.
  12. Lewandowski, D.; Drechsler, J.; Mach, S. von: Deriving query intents from web search engine queries (2012) 0.01
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    Abstract
    The purpose of this article is to test the reliability of query intents derived from queries, either by the user who entered the query or by another juror. We report the findings of three studies. First, we conducted a large-scale classification study (~50,000 queries) using a crowdsourcing approach. Next, we used clickthrough data from a search engine log and validated the judgments given by the jurors from the crowdsourcing study. Finally, we conducted an online survey on a commercial search engine's portal. Because we used the same queries for all three studies, we also were able to compare the results and the effectiveness of the different approaches. We found that neither the crowdsourcing approach, using jurors who classified queries originating from other users, nor the questionnaire approach, using searchers who were asked about their own query that they just entered into a Web search engine, led to satisfying results. This leads us to conclude that there was little understanding of the classification tasks, even though both groups of jurors were given detailed instructions. Although we used manual classification, our research also has important implications for automatic classification. We must question the success of approaches using automatic classification and comparing its performance to a baseline from human jurors.
  13. Behnert, C.; Lewandowski, D.: ¬A framework for designing retrieval effectiveness studies of library information systems using human relevance assessments (2017) 0.01
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    Abstract
    Purpose This paper demonstrates how to apply traditional information retrieval evaluation methods based on standards from the Text REtrieval Conference (TREC) and web search evaluation to all types of modern library information systems including online public access catalogs, discovery systems, and digital libraries that provide web search features to gather information from heterogeneous sources. Design/methodology/approach We apply conventional procedures from information retrieval evaluation to the library information system context considering the specific characteristics of modern library materials. Findings We introduce a framework consisting of five parts: (1) search queries, (2) search results, (3) assessors, (4) testing, and (5) data analysis. We show how to deal with comparability problems resulting from diverse document types, e.g., electronic articles vs. printed monographs and what issues need to be considered for retrieval tests in the library context. Practical implications The framework can be used as a guideline for conducting retrieval effectiveness studies in the library context. Originality/value Although a considerable amount of research has been done on information retrieval evaluation, and standards for conducting retrieval effectiveness studies do exist, to our knowledge this is the first attempt to provide a systematic framework for evaluating the retrieval effectiveness of twenty-first-century library information systems. We demonstrate which issues must be considered and what decisions must be made by researchers prior to a retrieval test.
  14. Lewandowski, D.: Suchmaschinen verstehen : 3. vollständig überarbeitete und erweiterte Aufl. (2021) 0.01
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    Abstract
    Suchmaschinen dienen heute selbstverständlich als Werkzeuge, um Informationen zu recherchieren. Doch wie funktionieren diese genau? Das Buch betrachtet Suchmaschinen aus vier Perspektiven: Technik, Nutzung, Recherche und gesellschaftliche Bedeutung. Es bietet eine klar strukturierte und verständliche Einführung in die Thematik. Zahlreiche Abbildungen erlauben eine schnelle Erfassung des Stoffs. Rankingverfahren und Nutzerverhalten werden dargestellt. Dazu kommen grundlegende Betrachtungen des Suchmaschinenmarkts, der Suchmaschinenoptimierung und der Rolle der Suchmaschinen als technische Informationsvermittler. Das Buch richtet sich an alle, die ein umfassendes Verständnis dieser Suchwerkzeuge erlangen wollen, u.a. Suchmaschinenoptimierer, Entwickler, Informationswissenschaftler, Bibliothekare sowie Online-Marketing-Verantwortliche. Für die dritte Auflage wurde der Text vollständig überarbeitet sowie alle Statistiken und Quellen auf den neuesten Stand gebracht.