Search (1 results, page 1 of 1)

  • × author_ss:"Frandsen, T.F."
  • × author_ss:"Rousseau, R."
  • × theme_ss:"Citation indexing"
  1. Frandsen, T.F.; Rousseau, R.: Article impact calculated over arbitrary periods (2005) 0.00
    2.497293E-4 = product of:
      0.0049945856 = sum of:
        0.0049945856 = weight(_text_:in in 3264) [ClassicSimilarity], result of:
          0.0049945856 = score(doc=3264,freq=4.0), product of:
            0.039165888 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.02879306 = queryNorm
            0.12752387 = fieldWeight in 3264, product of:
              2.0 = tf(freq=4.0), with freq of:
                4.0 = termFreq=4.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.046875 = fieldNorm(doc=3264)
      0.05 = coord(1/20)
    
    Abstract
    In this paper we address the various formulations of impact of articles, usually groups of articles as gauged by citations that these articles receive over a certain period of time. The journal impact factor, as published by ISI (Philadelphia, PA), is the best-known example of a formulation of impact of journals (considered as a set of articles) but many others have been defined in the literature. Impact factors have varying publication and citation periods and the chosen length of these periods enables, e.g., a distinction between synchronous and diachronous impact factors. It is shown how an impact factor for the general case can be defined. Two alternatives for a general impact factor are proposed, depending an whether different publication years are seen as a whole, and hence treating each one of them differently, or by operating with citation periods of identical length but allowing each publication period different starting points.