Page 156 - Becoming Metric Wise
P. 156

147
                                                    Publication and Citation Analysis























              Figure 5.8 Recognition line for a sleeping beauty. Based on (Ke et al., 2015).


              where c m 5 c(t m ) is assumed to be strictly positive. If c m 5 0 then B(T) 5 0.
              If t m 5 t(0) then B(T) is not defined.
                 Otherwise,

                                                            !
                                           c m 2 cð0Þ
                                      t m
                                     X          t 1 cð0Þ 2 cðtÞ
                              BðTÞ 5         t m                         (5.13)
                                              maxf1; cðtÞg
                                      t50
                 The calculation of B(T), according to Ke et al. (2015), is illustrated in
              Fig. 5.8.
                 The numerator of a term in B(T) is equal to the—signed—difference
              between the recognition line and the citation value. As the denominator
              of this term is equal to the number of citations (unless this number is
              zero, in which case the denominator is 1) each term in the sum deter-
              mining B(T) is a relative value.
                 If c(t) has a concave trajectory then B(T) is negative.
                 If c(t) is linear then B(T) is close to zero.
                 If c(t) is convex then B(T) is positive.
                 In the discussion that follows we assume that each term in the sum
              determining B(T) is nonnegative. Then the following properties hold.
              •  All else staying the same, B(T) is increasing when c m increases.
              •  All else staying the same, B(T) decreases when c(t), with t fixed and
                 different from 0 or t m , increases as the numerator decreases and the
                 denominator increases.
   151   152   153   154   155   156   157   158   159   160   161