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New developments in electronic publishing and bibliometrics. Henk F. Moed CWTS, Leiden University, Netherlands Elsevier, Amsterdam, Netherlands. Contents. Contents. Journal impact measures are no good predictors of an individual paper’s actual citation impact.
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New developments in electronic publishing and bibliometrics Henk F. Moed CWTS, Leiden University, Netherlands Elsevier, Amsterdam, Netherlands
Journal impact measures are no good predictors of an individual paper’s actual citation impact Partly based on International Mathematical Union’s Report ‘Citation Statistics’ (2008)
What is the probability that ....... Almost zero a randomly selected PAMS paper is cited at least as often as a randomly selected TAMS paper? 62 %
Thomson/JCR Journal Impact Factor Citations to all docs # Citable docs
The problem of “free” citations - 1 Cites + + + + + Docs + + + + +
The problem of “free” citations - 2 “Free” Citations Cites + + + + + Docs + +
All three publication lists have a Hirsch Index of 5 Author 1 Author 2 Author 3 30 P1 10 P2 8 P3 6 P4 5 P5 1 P6 0 P7 30 P1 10 P2 8 P3 6 P4 5 P5 4 P6 4 P7 4 P8 4 P9 100 P1 70 P2 8 P3 6 P4 5 P5 1 P6 0 P7 1 2 3 4 5 6 7 8 9 H=? H=? H=? 5 5 5
University ranking positions are primarily marketing tools, not research management tools
Research assessment methodologies must take into account… [EC AUBR Expert Group] • Inclusive definition of research / output • Different types of research and its impacts • Differences among research fields • Type and mission of institution • Proper units of assessment • Policy context, purpose and user needs • The European dimension • Need to be valid, fair and practically feasible
Top-down institutional analysis Select an institution’s papers using author addresses (incl. verification) Categorize articles into research fields Calculate indicators Compare with benchmarks
Bottom-up institutional analysis (CWTS) Compile a list of researchers Compile a list of publications per researcher (incl. verification) Aggregate researchers into groups, departments, fields, etc. Calculate indicators; compare with benchmarks
Case study: A national Research Council • Proposals evaluated by committees covering a discipline • Reports from external referees • Committee members can be applicants
Affinity applicants – Committee 0 Applicants are/were not member of any Committee • Co-applicant is/was member of a Committee, but notof the one evaluating • Firstapplicant is/was member of a Committee, but not of the one evaluating • Co-applicant is member of the Committee(s) evaluating the proposal • Firstapplicant is member of the Committee(s) evaluating the proposal
For 15 % of applications an applicant is a member of the evaluating Committee (Affinity=3, 4)
Probability to be granted increases with increasing affinity applicants-Committee
Logistic regression analysis:Affinity Applicant-Committee has a significant effect upon the probability to be granted MAXIMUM-LIKELIHOOD ANALYSIS-OF-VARIANCE TABLE (N=2,499) Source DF Chi-Square Prob ------------------------------------------------------------- INTERCEPT 1 18.47 0.0000 Publ Impact applicant 3 26.97 0.0000 ** Rel transdisc impact applicant 1 0.29 0.5926 Affinity applicant-Committee2 112.50 0.0000 ** Sum requested 1 45.47 0.0000 ** Institution applicant 4 25.94 0.0000 ** LIKELIHOOD RATIO 199 230.23 0.0638
The future of research assessment exercises lies in the intelligent combination of metrics and peer review
Effects of editorial self-citations upon journal impact factors[Reedijk & Moed, J. Doc., 2008] Editorial self-citations: A journal editor cites in his editorials papers published in his own journal Focus on ‘consequences’ rather than ‘motives’
Case: ISI/JCR Impact Factor of a Gerontology Journal (published in the journal itself)
Decomposition of the IF of a Gerontology journal Editorial self citations Free citations
One can identify and correct for the following types of strategic editorial behavior Publish ‘non-citable’ items Publish more reviews Publish ‘top’ papers in January Publish ‘topical’ papers (with high short term impact) Cite your journal in your own editorials Excessive journal self-citing
Journal articles Not deposited in OA rep. (no) Deposited in OA rep (o) ?><= Average Impact (CPPo) Average Impact (CPPno)
ArXiv, Cond Mat Phys [Moed, JASIST 2007] ArXiv papers appear earlier EarlyView Effect 100 Quality Bias: Better authors use ArXiv
Age distribution of citations to Arxiv and non-ArXiv papers Move curve by 6 months to the right
Early view effect: Citations to papers deposited in ArXiv-CM start about 6 months earlier
More research questions • Early view effect also visible in a non-OA environment? • Citation impact measured in biased sample?
Downloads vs. Citations More downloads more citations or More citations more downloads?
Relation between citations and internet hits for 153 papers in volume 318 of the BMJ (1999)Figure 1 from: Perneger, TV. BMJ. 2004, 329 (7465): 546–547. Relation between online “hit counts” and subsequent citations: prospective study of research papers in the BMJ
Age distribution downloads vs. citations[Tetrahedron Lett, ScienceDirect; Moed, JASIST, 2005] Downloads % Citations Age (months)
Ageing downloads vs. citations: Two factor vs. single factor model Downloads % Citations Age (months)
Citations lead to downloads[Moed, J. Am Soc Inf Sci Techn, 2005] Paper B published; it cites A Paper C published; it cites A and B Paper A published Download of A increases