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at least one active reference in the citing journal. The first problem men-
tioned in relation to the original SNIP-index, is solved as adding one cita-
tion clearly increases the new SNIP. Also the second problem is solved. For
this we refer the reader to Waltman et al. (2013). These authors also show
that indeed SNIP corrects for differences between citation potentials.

6.12.3 Comments
Waltman et al. (2013) observed some problems inherent in the formula
for the original SNIP indicator and proposed a revised version that solves
these problems. Yet, the price that has to be paid for this is that its calcu-
lation has become more complicated. The harmonic mean is less intuitive
than the arithmetic mean or the median; the proportion of publications
that have at least one active reference is introduced as a new parameter,
and several ad hoc decisions have been made, for instance the decision to
exclude journals with less than 20% (why 20, not 15 or 10%?) of the pub-
lications in the year of analysis having at least one active reference. Yet, as
Elsevier—Scopus is using the modified SNIP since October 18, 2012 this
new version is the only “official” one. Moed (2016) expresses doubts
about the necessity of the changes that have been made on his original
version. He concludes that none of the two indicators is superior to the
other as they are both based on plausible statistical assumptions. He notes
that the modified SNIP calculation strongly emphasizes the requirement
to comply with certain consistency criteria, while the original SNIP can
be interpreted as a correction to a subject field bias in the classical JIF as
calculated in the WoS. Moreover, Mingers (2014) points out that, by
using a harmonic mean the new SNIP result can be significantly depen-
dent on the dispersion of the number of references as well as their vol-
ume. He sees no justification for this procedure as the point of
normalization is to make allowance for the volume of activity not its
degree of variability. A large part of this discussion of the SNIP-index
and its revision is taken from (Rousseau, 2013).
Finally, JIFs, however calculated, can only have a minor or restricted
meaning in evaluations for fields where conference proceedings, contri-
butions in edited books or monographs play an important role.

6.13 CLARIVATE ANALYTICS’ JOURNAL CITATION REPORTS

The first edition of the JCR dates from 1976 (Garfield, 1976). It was
added to the Science Citation Index 1975 as volume 9 and covers the