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Journal Citation Analysis

W(Y,Y 0 ). The advantage of this approach is that journals with short refer-
ence lists such as most trade journals (journals geared towards professionals
in a discipline) are not anymore favored with respect to other journals in
the same field. A disadvantage of this approach is that the audience factor
becomes dependent on the used journal classification scheme.

6.12 THE SNIP INDICATOR (MOED, 2010, 2016;
WALTMAN ET AL., 2013)
6.12.1 Definition of the SNIP Indicator

The SNIP-indicator, where SNIP stands for Source Normalized Impact
per Paper, was introduced by Moed in 2010 (Moed, 2010) and is available,
in revised form, in Elsevier’s Scopus database. The idea of a source normal-
ized approach is to correct for differences in citation practices between sci-
entific fields. This is done by taking the length of the reference lists of
citing papers into account. The underlying idea is that it is better to receive
one citation among 10, than to receive one citation among 70. Other
advantages are that scientific fields do not depend on a journal (as do the
JCR categories) but depend on articles’ references. Consequently this
approach can also be used for multidisciplinary journals such as Nature and
Science. By its construction it corrects for differences in citation habits.
The original SNIP indicator was defined as a ratio, namely the ratio
of a raw impact per paper (RIP) and a relative database citation potential
(RDCP):
RIP
SNIP 5 (6.16)
RDCP
The raw impact (RIP) is very similar to the standard JIF as available in
the WoS but is calculated over 3 years while the JIF is calculated over a
citation window of 2 years. Only publications of article type, conference
papers and reviews (as defined in Scopus) are taken into account in the
calculation of the SNIP.
The denominator RDCP is defined as the ratio of the journal’s DCP
(Database Citation Potential) and the median DCP of the database. The
DCP-value of a journal is determined by the following procedure. First, a
journal’s subject field is determined. This subject field is defined as the set
of all publications in the year of analysis with at least one reference to the
journal (going back no more than 8 years). Then the DCP value of a
journal equals the average number of references in the publications in the
subject field of the journal, counting only recent references, i.e., refer-
ences to publications that appeared in the three preceding years in