  In their article, entitled "Towards a new crown indicator: some theoretical
considerations," Waltman et al. (2010; at arXiv:1003.2167) show that the "old
crown indicator" of CWTS in Leiden was mathematically inconsistent and that one
should move to the normalization as applied in the "new crown indicator."
Although we now agree about the statistical normalization, the "new crown
indicator" inherits the scientometric problems of the "old" one in treating
subject categories of journals as a standard for normalizing differences in
citation behavior among fields of science.
  We further note that the "mean" is not a proper statistics for measuring
differences among skewed distributions. Without changing the acronym of "MNCS,"
one could define the "Median Normalized Citation Score." This would relate the
new crown indicator directly to the percentile approach that is, for example,
used in the Science and Engineering Indicators of US National Science Board
(2010). The median is by definition equal to the 50th percentile. The indicator
can thus easily be extended with the 1% (= 99th percentile) most highly-cited
papers (Bornmann et al., in press). The seeming disadvantage of having to use
non-parametric statistics is more than compensated by possible gains in the
precision.
