Page 270 - Becoming Metric Wise

262 Becoming Metric-Wise

The CWTS Leiden Rankings are focused on research and do not
include teaching or reputation. No composite indicator is provided;
instead, users choose themselves which indicators fit best for their own
purposes.
In the 2016 edition, two types of indicators are provided: indicators of
research impact and indicators of research collaboration. The impact indi-
cators can be divided into size-dependent and size-independent ones.
• Size-dependent impact indicators are the overall number of publica-
tions and the number of publications in the top n%(n 5 1, 10 or 50)
most frequently cited publications in the same year and same field.
• The size-independent impact indicators are the proportion of publica-
tions in the top n%(n 5 1, 10 or 50) most frequently cited publica-
tions in the same year and same field. Before 2015, average-based
indicators like MCS and MNCS were also included. Note that, con-
trary to several other university rankings, the Leiden ranking corrects
for size by taking into account the number of publications rather than
the number of academic staff.
The collaboration indicators can also be divided into size-dependent
and size-independent ones. The size-dependent collaboration indicators
are:
• Collaboration: number of publications written in collaboration with
another institution.
• International collaboration: number of publications written in collabo-
ration with an institution from another country.
• Short distance collaborations: number of publications written in col-
laboration with an institution located within 100 km.
• Long distance collaborations: number of publications written in col-
laboration with an institution located over 5000 km away.
The 4 size-independent collaboration indicators are based on the same
data, but use the proportion instead of the number of collaborations.
Compared with other university rankings, the Leiden Ranking offers
more advanced indicators of scientific impact and collaboration and uses a
more transparent methodology. The Leiden Ranking does not rely on
subjective data obtained from reputational surveys or on data provided by
universities themselves. Also, the Leiden Ranking refrains from aggregating
different dimensions of university performance into a single overall indica-
tor. New in the 2016 edition is that, in addition to the classic list view, the
indicators can also be visualized on a scatter plot (chart view) and on a
geographic map (map view).