Search (10 results, page 1 of 1)

0.0061617517 = product of:
  0.049294014 = sum of:
    0.049294014 = weight(_text_:studies in 3144) [ClassicSimilarity], result of:
      0.049294014 = score(doc=3144,freq=4.0), product of:
        0.15812531 = queryWeight, product of:
          3.9902744 = idf(docFreq=2222, maxDocs=44218)
          0.03962768 = queryNorm
        0.3117402 = fieldWeight in 3144, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          3.9902744 = idf(docFreq=2222, maxDocs=44218)
          0.0390625 = fieldNorm(doc=3144)
  0.125 = coord(1/8)

Abstract

Users of web search engines are known to mostly focus on the top ranked results of the search engine result page. While many studies support this well known information seeking pattern only few studies concentrate on the question what users are missing by neglecting lower ranked results. To learn more about the relevance distributions in the so-called long tail we conducted a relevance assessment study with the Million Short long-tail web search engine. While we see a clear difference in the content between the head and the tail of the search engine result list we see no statistical significant differences in the binary relevance judgments and weak significant differences when using graded relevance. The tail contains different but still valuable results. We argue that the long tail can be a rich source for the diversification of web search engine result lists but it needs more evaluation to clearly describe the differences.

0.005114809 = product of:
  0.040918473 = sum of:
    0.040918473 = weight(_text_:libraries in 1909) [ClassicSimilarity], result of:
      0.040918473 = score(doc=1909,freq=6.0), product of:
        0.13017908 = queryWeight, product of:
          3.2850544 = idf(docFreq=4499, maxDocs=44218)
          0.03962768 = queryNorm
        0.3143245 = fieldWeight in 1909, product of:
          2.4494898 = tf(freq=6.0), with freq of:
            6.0 = termFreq=6.0
          3.2850544 = idf(docFreq=4499, maxDocs=44218)
          0.0390625 = fieldNorm(doc=1909)
  0.125 = coord(1/8)

Abstract

Purpose - The general science portal "vascoda" merges structured, high-quality information collections from more than 40 providers on the basis of search engine technology (FAST) and a concept which treats semantic heterogeneity between different controlled vocabularies. First experiences with the portal show some weaknesses of this approach which come out in most metadata-driven Digital Libraries (DLs) or subject specific portals. The purpose of the paper is to propose models to reduce the semantic complexity in heterogeneous DLs. The aim is to introduce value-added services (treatment of term vagueness and document re-ranking) that gain a certain quality in DLs if they are combined with heterogeneity components established in the project "Competence Center Modeling and Treatment of Semantic Heterogeneity". Design/methodology/approach - Two methods, which are derived from scientometrics and network analysis, will be implemented with the objective to re-rank result sets by the following structural properties: the ranking of the results by core journals (so-called Bradfordizing) and ranking by centrality of authors in co-authorship networks. Findings - The methods, which will be implemented, focus on the query and on the result side of a search and are designed to positively influence each other. Conceptually, they will improve the search quality and guarantee that the most relevant documents in result sets will be ranked higher. Originality/value - The central impact of the paper focuses on the integration of three structural value-adding methods, which aim at reducing the semantic complexity represented in distributed DLs at several stages in the information retrieval process: query construction, search and ranking and re-ranking.

Footnote

Beitrag eines Themenheftes "Digital libraries and the semantic web: context, applications and research".

0.0035436437 = product of:
  0.02834915 = sum of:
    0.02834915 = weight(_text_:libraries in 649) [ClassicSimilarity], result of:
      0.02834915 = score(doc=649,freq=2.0), product of:
        0.13017908 = queryWeight, product of:
          3.2850544 = idf(docFreq=4499, maxDocs=44218)
          0.03962768 = queryNorm
        0.2177704 = fieldWeight in 649, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.2850544 = idf(docFreq=4499, maxDocs=44218)
          0.046875 = fieldNorm(doc=649)
  0.125 = coord(1/8)

Abstract

This paper is about a better understanding of the structure and dynamics of science and the usage of these insights for compensating the typical problems that arises in metadata-driven Digital Libraries. Three science model driven retrieval services are presented: co-word analysis based query expansion, re-ranking via Bradfordizing and author centrality. The services are evaluated with relevance assessments from which two important implications emerge: (1) precision values of the retrieval services are the same or better than the tf-idf retrieval baseline and (2) each service retrieved a disjoint set of documents. The different services each favor quite other - but still relevant - documents than pure term-frequency based rankings. The proposed models and derived retrieval services therefore open up new viewpoints on the scientific knowledge space and provide an alternative framework to structure scholarly information systems.

0.0034856133 = product of:
  0.027884906 = sum of:
    0.027884906 = weight(_text_:studies in 250) [ClassicSimilarity], result of:
      0.027884906 = score(doc=250,freq=2.0), product of:
        0.15812531 = queryWeight, product of:
          3.9902744 = idf(docFreq=2222, maxDocs=44218)
          0.03962768 = queryNorm
        0.17634688 = fieldWeight in 250, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.9902744 = idf(docFreq=2222, maxDocs=44218)
          0.03125 = fieldNorm(doc=250)
  0.125 = coord(1/8)

Content

This study investigates the development of open access (OA) to journal articles from authors affiliated with German universities and non-university research institutions in the period 2010-2018. Beyond determining the overall share of openly available articles, a systematic classification of distinct categories of OA publishing allowed us to identify different patterns of adoption of OA. Taking into account the particularities of the German research landscape, variations in terms of productivity, OA uptake and approaches to OA are examined at the meso-level and possible explanations are discussed. The development of the OA uptake is analysed for the different research sectors in Germany (universities, non-university research institutes of the Helmholtz Association, Fraunhofer Society, Max Planck Society, Leibniz Association, and government research agencies). Combining several data sources (incl. Web of Science, Unpaywall, an authority file of standardised German affiliation information, the ISSN-Gold-OA 3.0 list, and OpenDOAR), the study confirms the growth of the OA share mirroring the international trend reported in related studies. We found that 45% of all considered articles during the observed period were openly available at the time of analysis. Our findings show that subject-specific repositories are the most prevalent type of OA. However, the percentages for publication in fully OA journals and OA via institutional repositories show similarly steep increases. Enabling data-driven decision-making regarding the implementation of OA in Germany at the institutional level, the results of this study furthermore can serve as a baseline to assess the impact recent transformative agreements with major publishers will likely have on scholarly communication.

0.0029530365 = product of:
  0.023624292 = sum of:
    0.023624292 = weight(_text_:libraries in 3106) [ClassicSimilarity], result of:
      0.023624292 = score(doc=3106,freq=2.0), product of:
        0.13017908 = queryWeight, product of:
          3.2850544 = idf(docFreq=4499, maxDocs=44218)
          0.03962768 = queryNorm
        0.18147534 = fieldWeight in 3106, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.2850544 = idf(docFreq=4499, maxDocs=44218)
          0.0390625 = fieldNorm(doc=3106)
  0.125 = coord(1/8)

Source

Proceedings of the 15th European Networked Knowledge Organization Systems Workshop (NKOS 2016) co-located with the 20th International Conference on Theory and Practice of Digital Libraries 2016 (TPDL 2016), Hannover, Germany, September 9, 2016. Edi. by Philipp Mayr et al. [http://ceur-ws.org/Vol-1676/=urn:nbn:de:0074-1676-5]

0.002348939 = product of:
  0.018791512 = sum of:
    0.018791512 = product of:
      0.037583023 = sum of:
        0.037583023 = weight(_text_:22 in 5991) [ClassicSimilarity], result of:
          0.037583023 = score(doc=5991,freq=2.0), product of:
            0.13876937 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.03962768 = queryNorm
            0.2708308 = fieldWeight in 5991, 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=5991)
      0.5 = coord(1/2)
  0.125 = coord(1/8)

Date

8. 7.2006 21:06:22

0.002348939 = product of:
  0.018791512 = sum of:
    0.018791512 = product of:
      0.037583023 = sum of:
        0.037583023 = weight(_text_:22 in 2618) [ClassicSimilarity], result of:
          0.037583023 = score(doc=2618,freq=2.0), product of:
            0.13876937 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.03962768 = queryNorm
            0.2708308 = fieldWeight in 2618, 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=2618)
      0.5 = coord(1/2)
  0.125 = coord(1/8)

Source

Metadata for semantic and social applications : proceedings of the International Conference on Dublin Core and Metadata Applications, Berlin, 22 - 26 September 2008, DC 2008: Berlin, Germany / ed. by Jane Greenberg and Wolfgang Klas

0.0023251986 = product of:
  0.018601589 = sum of:
    0.018601589 = product of:
      0.037203178 = sum of:
        0.037203178 = weight(_text_:area in 542) [ClassicSimilarity], result of:
          0.037203178 = score(doc=542,freq=2.0), product of:
            0.1952553 = queryWeight, product of:
              4.927245 = idf(docFreq=870, maxDocs=44218)
              0.03962768 = queryNorm
            0.19053608 = fieldWeight in 542, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              4.927245 = idf(docFreq=870, maxDocs=44218)
              0.02734375 = fieldNorm(doc=542)
      0.5 = coord(1/2)
  0.125 = coord(1/8)

Abstract

In the final phase of the project, a major evaluation effort is under way to test and measure the effectiveness of the vocabulary mappings in an information system environment. Actual user queries are tested in a distributed search environment, where several bibliographic databases with different controlled vocabularies are searched at the same time. Three query variations are compared to each other: a free-text search without focusing on using the controlled vocabulary or terminology mapping; a controlled vocabulary search, where terms from one vocabulary (a 'home' vocabulary thought to be familiar to the user of a particular database) are used to search all databases; and finally, a search, where controlled vocabulary terms are translated into the terms of the respective controlled vocabulary of the database. For evaluation purposes, types of cross-concordances are distinguished between intradisciplinary vocabularies (vocabularies within the social sciences) and interdisciplinary vocabularies (social sciences to other disciplines as well as other combinations). Simultaneously, an extensive quantitative analysis is conducted aimed at finding patterns in terminology mappings that can explain trends in the effectiveness of terminology mappings, particularly looking at overlapping terms, types of determined relations (equivalence, hierarchy etc.), size of participating vocabularies, etc. This project is the largest terminology mapping effort in Germany. The number and variety of controlled vocabularies targeted provide an optimal basis for insights and further research opportunities. To our knowledge, terminology mapping efforts have rarely been evaluated with stringent qualitative and quantitative measures. This research should contribute in this area. For the NKOS workshop, we plan to present an overview of the project and participating vocabularies, an introduction to the heterogeneity service and its application as well as some of the results and findings of the evaluation, which will be concluded in August.

0.0020133762 = product of:
  0.01610701 = sum of:
    0.01610701 = product of:
      0.03221402 = sum of:
        0.03221402 = weight(_text_:22 in 328) [ClassicSimilarity], result of:
          0.03221402 = score(doc=328,freq=2.0), product of:
            0.13876937 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.03962768 = queryNorm
            0.23214069 = fieldWeight in 328, 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=328)
      0.5 = coord(1/2)
  0.125 = coord(1/8)

Date

22. 7.2012 19:25:54

0.0016778135 = product of:
  0.013422508 = sum of:
    0.013422508 = product of:
      0.026845016 = sum of:
        0.026845016 = weight(_text_:22 in 2627) [ClassicSimilarity], result of:
          0.026845016 = score(doc=2627,freq=2.0), product of:
            0.13876937 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.03962768 = queryNorm
            0.19345059 = fieldWeight in 2627, 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=2627)
      0.5 = coord(1/2)
  0.125 = coord(1/8)

Source

Metadata for semantic and social applications : proceedings of the International Conference on Dublin Core and Metadata Applications, Berlin, 22 - 26 September 2008, DC 2008: Berlin, Germany / ed. by Jane Greenberg and Wolfgang Klas