Page 176 - Becoming Metric Wise

168 Becoming Metric-Wise

always clear if a publication is “citable” or not, in particular for multidis-
ciplinary journals who have a lot of article types. The recently introduced
CiteScore index (see Section 6.16) ignores this distinction and considers
all journal publications as citable.

6.8 THE H-INDEX FOR JOURNALS

The h-index was originally introduced as a lifetime citation indicator for
individual scientists (Hirsch, 2005). We come back to the original version
in the next chapter. Yet, it was soon recognized that, being an indicator
based on publications and citations, it could also be applied to journals
(Braun et al., 2005). Today’s h-index of journal J for the publication year
Y is determined as follows. One collects all publications in journal J in
year Y and determines the number of citations received by each of these
publications (until the day of the data collection) in the used database.
This list is ranked according to the number of received citations. Then
the h-index of this journal and for the publication year Y is the largest
natural number h such that the first h articles have received each at least h
citations. As this value may change day by day it is an instantaneous indi-
cator. Besides the h-index described here, one may calculate a journal
h-index based on all the journal’s publications (since its inception; this is
similar to a scientist’s career h-index). It is also possible to calculate an
index for the same publication and citation window as for the standard
synchronous JIF. This has been mentioned explicitly in Liang and
Rousseau (2009).
Returning to Table 6.1 we extract the data necessary to calculate the
h-index of this journal using the periods of this table. This is shown in
Table 6.9.
The h-index can now be calculated from Table 6.10 where articles are
ranked according to the number of received citations. Clearly, this
h-index is equal to 5.

Table 6.9 The p-c matrix required to calculate the h-index of the (fictitious) journal
represented by Table 6.1
Articles A B C D E F G H I J K L
Citations received during the 19 5 3 10 16 6 1 2 4 1 2 3
period: year 1 year 4