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  • 1.
    Ahlgren, Per
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Query Expansion2002Inngår i: Human IT, ISSN 1402-1501, E-ISSN 1402-151X, Vol. 5, nr 4, s. 157-Artikkel i tidsskrift (Fagfellevurdert)
  • 2.
    Ahlgren, Per
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Query Expansion2002Inngår i: Human IT, ISSN 1402-1501, E-ISSN 1402-151X, Vol. 5, nr 4, s. 157-Artikkel i tidsskrift (Fagfellevurdert)
  • 3.
    Ahlgren, Per
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    The effects of indexing strategy-query term combination on retrieval effectiveness in a Swedish full text database2004Doktoravhandling, monografi (Annet vitenskapelig)
  • 4.
    Ahlgren, Per
    et al.
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Grönqvist, Leif
    Evaluation of retrieval effectiveness with incomplete relevance data: theoretical and experimental comparison of three measures2008Inngår i: Information Processing & Management, ISSN 0306-4573, E-ISSN 1873-5371, Vol. 44, nr 1, s. 212-225Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper investigates two relatively new measures of retrieval effectiveness in relation to the problem of incomplete relevance data. The measures, Bpref and RankEff, which do not take into account documents that have not been relevance judged, are compared theoretically and experimentally. The experimental comparisons involve a third measure, the well-known mean uninterpolated average precision. The results indicate that RankEff is the most stable of the three measures when the amount of relevance data is reduced, with respect to system ranking and absolute values. In addition, RankEff has the lowest error-rate.

  • 5.
    Ahlgren, Per
    et al.
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Grönqvist, Leif
    Measuring retrieval effectiveness with incomplete relevance data2006Inngår i: Current Research in Information Sciences and Technologies. Multidisciplinary approaches to global information systems / [ed] Vicente P Guerrero-Bote, Open Institute of Knowledge , 2006, s. 74-Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 6.
    Ahlgren, Per
    et al.
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Grönqvist, Leif
    Retrieval evaluation with incomplete relevance data: a comparative study of three measures2006Konferansepaper (Fagfellevurdert)
  • 7.
    Ahlgren, Per
    et al.
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Jarneving, Bo
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Bibliographic coupling, common abstract stems and clustering: a comparison of two document-document similarity approaches in the context of science mapping2008Inngår i: Scientometrics, ISSN 0138-9130, E-ISSN 1588-2861, Vol. 76, nr 2, s. 273-290Artikkel i tidsskrift (Fagfellevurdert)
  • 8.
    Ahlgren, Per
    et al.
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Jarneving, Bo
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Rousseau, R.
    Requirements for a cocitation similarity measure, with special reference to Pearson's correlation coefficient2003Inngår i: Journal of The American Society For Information Science And Technology, ISSN 1532-2882, E-ISSN 1532-2890, Vol. 54, nr 6, s. 550-560Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    Ahlgren, Jarneving, and. Rousseau review accepted procedures for author co-citation analysis first pointing out that since in the raw data matrix the row and column values are identical i,e, the co-citation count of two authors, there is no clear choice for diagonal values. They suggest the number of times an author has been co-cited with himself excluding self citation rather than the common treatment as zeros or as missing values. When the matrix is converted to a similarity matrix the normal procedure is to create a matrix of Pearson's r coefficients between data vectors. Ranking by r and by co-citation frequency and by intuition can easily yield three different orders. It would seem necessary that the adding of zeros to the matrix will not affect the value or the relative order of similarity measures but it is shown that this is not the case with Pearson's r. Using 913 bibliographic descriptions form the Web of Science of articles form JASIS and Scientometrics, authors names were extracted, edited and 12 information retrieval authors and 12 bibliometric authors each from the top 100 most cited were selected. Co-citation and r value (diagonal elements treated as missing) matrices were constructed, and then reconstructed in expanded form. Adding zeros can both change the r value and the ordering of the authors based upon that value. A chi-squared distance measure would not violate these requirements, nor would the cosine coefficient. It is also argued that co-citation data is ordinal data since there is no assurance of an absolute zero number of co-citations, and thus Pearson is not appropriate. The number of ties in co-citation data make the use of the Spearman rank order coefficient problematic.

  • 9.
    Ahlgren, Per
    et al.
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Jarneving, Bo
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Rousseau, Ronald
    Letter to the editor. Author Cocitation Analysis and Pearson's r2004Inngår i: Journal of The American Society For Information Science And Technology, ISSN 1532-2882, E-ISSN 1532-2890, Vol. 9, nr 55, s. 843-844Artikkel i tidsskrift (Annet vitenskapelig)
  • 10.
    Ahlgren, Per
    et al.
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Jarneving, Bo
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Rousseau, Ronald
    Letter to the editor. Rejoinder: In Defense of Formal Methods2004Inngår i: Journal of The American Society For Information Science And Technology, ISSN 1532-2882, E-ISSN 1532-2890, Vol. 10, nr 55, s. 935-936Artikkel i tidsskrift (Annet vitenskapelig)
  • 11.
    Ahlgren, Per
    et al.
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Kekäläinen, Jaana
    Indexing strategies for Swedish full text retrieval under different user scenarios2007Inngår i: Information Processing & Management, ISSN 0306-4573, E-ISSN 1873-5371, Vol. 43, nr 1, s. 81-102Artikkel i tidsskrift (Fagfellevurdert)
  • 12.
    Ahlgren, Per
    et al.
    Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan.
    Kekäläinen, Jaana
    Swedish full text retrieval: effectiveness of different combinations of indexing strategies with query terms2006Inngår i: Information retrieval (Boston), ISSN 1386-4564, E-ISSN 1573-7659, Vol. 9, nr 6, s. 681-Artikkel i tidsskrift (Fagfellevurdert)
1 - 12 of 12
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