Page 140 - Academic and Research Book_WEB

citations received in a given year to publications published in the previous three years divided by the
sum of publications in the same previous three years. CiteScore is calculated for the current year on a
monthly basis until it is fixed as a permanent value in May the following year, permitting a real-time
view on how the metric builds as citations accrue. Once fixed, the other CiteScore metrics are also
computed and contextualize this score with rankings and other indicators to allow comparison.

Metrics: g-index, h-index, i10-index

g-index

The g-index was proposed by Leo Egghe; g-index is calculated this way: “[Given a set of articles]
ranked in decreasing order of the number of citations that they received, the g-index is the (unique)
largest number such that the top g articles received (together) at least g^2 citations.” It accounts for the
performance of author’s top articles and helps to make more apparent the difference between authors’
respective impacts. The inflated values of g-index help to give credit to lowly-cited or non-cited
papers while giving credit for highly-cited papers.

h-index

Another author-level metric, the h-index (and some of its numerous variants) has come to be applied
to higher-order aggregations of research publications, including journals. A composite of productivity
and citation impact, h-index is defined as the greatest number of publications h for which the
count of lifetime citations is greater than or equal to h. Being bound at the upper limit only by total
productivity, h-index favours older and more productive authors and journals. As h-index can only
ever rise, it is also insensitive to recent changes in performance. Finally, the ease of increasing h-index
does not scale linearly: an author with an h-index of 2 needs only publish a third paper and have all
three of them cited at least three times to rise to an h-index of 3; an author with an h-index of 44 must
publish a 45th paper and have it and all the others attain 45 citations each before progressing to an
h-index of 45. h-index is therefore of limited usefulness to distinguish between authors, since most
have single-digit h-indexes.

i10-index

The i10-index is the newest in the line of journal metrics and was introduced by Google Scholar in
2011. It is a simple and straightforward indexing measure found by tallying a journal’s total number
1
of published papers with at least 10 citations.
Research metrics are sometimes controversial, especially when in popular use they become proxies
for multidimensional concepts such as research quality or impact. Each metric may offer a different
emphasis based on its underlying data source, method of calculation, or context of use. In this context,
use of multiple complementary metrics can help to provide a more complete picture and reflect
different aspects of research productivity and impact in the final assessment.

Endnote

1 Google Scholar Blog. 2011. https://scholar.googleblog.com/2011/11/google-scholar-citations-open-
to-all.html.

ACADEMIC INTEGRITY AND RESEARCH QUALITY | 129