Page 173 - Becoming Metric Wise

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Journal Citation Analysis

Table 6.8 Data used to calculate AGIF S (4,1,Y,Y 1 2)
Year Y-1 Y Y+1 Y+2 Y+3 Y+4
Publ. x x
Cit.Y-1 x - - - - -
Cit.Y x x - - - -
Cit.Y+1 x x x - - -
Cit.Y+2 x x x - -

Cit.Y+3 x x x x -
Cit.Y+4 x x x x x
Cit.Y+5 x x x x x
Cit.Y+6 x x x x x x
Cit.Y+7 x x x x x x

the journal belongs, leading to discipline impact factors (Hirst, 1978;
Kim, 1991) or, another discipline leading to the study of import/export
ratios (Rinia et al., 2002). One could imagine that one wants to study the
impact of a journal on so-called top publications by restricting the pool
to the journals Science and Nature.
The citation pool may also be expanded. This is necessary if one wants
to calculated a JIF or JDIF for a journal that is not covered by the WoS
or Scopus and one wants to include journal self-citations (Stegmann,
1999). Then the pool must be expanded by including the journal that is
not covered by the database one uses. Recall that a journal self-citation
occurs if an article published in journal J 1 cited another article which was
also published in journal J 1 .
If one uses the journal itself as the citation pool then one obtains a
journal self-impact factor. Usually the self-impact factor is lower than the
one obtained by using the whole database as a pool. Indeed, the denomi-
nator is the same in both cases, while the numerator is only the same in
the highly improbable case that a journal only receives citations from arti-
cles published in the journal itself.

6.7.2 Normalization
If we consider the subject category Family studies in the JCR for 2014,
we see that the highest impact factor in this category is 2.833. That is