Essential Science IndicatorsSM
Understanding Core Data - Institutions
Scientific research is performed within the context of an institution,
and thus the recognition afforded the individual researchers affiliated
with that institution is reflected in the prestige and reputation of
the institution as a whole. By aggregating publications and citations
at the institutional level we can measure the institutional output and
prestige attributable to the affiliated researchers.
Counting method for papers and citations:
Institution counts are based on the author affiliations given on
the published papers. A paper is attributed to an institution if
the paper carries at least one author address of that institution.
All addresses are considered, not only the first-listed author
address. If an institution appears more than once on a paper, it is
considered only once for paper and citation counts. All unique
institutions on a paper are credited equally for the paper, and all
citations received by a paper are credited equally to all the
institutions on the cited paper. No restrictions are made on the
citing items in compiling the citation counts, other than that they
are recorded from Clarivate Analytics-indexed journals only.
Time period for counts (cites, papers, cites per
The time period for Essential Science Indicators counts is
10 years, plus partial year counts for the current year (data is
updated six times a year). This means that any papers in the 10+
year period can be cited by any items in that same period. Thomson
Reuters database years (the actual years when items are entered
into the Clarivate Analytics database, which is not necessarily the
publication year) are used to define the time periods.
Types of items counted:
Papers are defined as regular scientific articles, review articles,
proceedings papers, and research notes. Letters to the editor,
correction notices, and abstracts are not counted. Only Thomson
Reuters-indexed journal articles or papers are counted.
Essential Science Indicators counts are based on an
Clarivate Analytics journal set (see complete
journal list for
Essential Science Indicators) categorized into
22 broad fields.
Fields are defined by a unique grouping of journals, with no
journal being assigned to more than one field. The
Multidisciplinary field contains journals such as Science
and Nature which in an article level
would be assigned to specific fields. This should be taken into
account when analyzing the field ranking of an individual
scientist, institution, or country.
Institutions selected for listing in Essential Science
Indicators must meet a cumulative citation count threshold for
the 10+ year period. The thresholds are set separately for each
field. More information about the actual
Essential Science Indicators.
The absence of an institution's name in Essential Science
Indicators means that the institution did not meet the
citation threshold in any field.
Institutions having the same name may represent more than one
institution. This might be a similarly named institution in some
other geographic location. Examining highly cited papers for such
an institution will reveal whether institutions at different
locations are involved.
Institutions may appear with different name abbreviations, in which
case more than one entry may need to be consulted. In general, the
name listed is as published with the exception of overt variants
that have been identified, changed to a preferred form, and added
to a unification dictionary. Unification (unifying the varying ways
institutional names are given) is based only on the first segment
of the author address. For example, the address HARVARD UNIV,
BRIGHAM & WOMEN'S HOSP, would be given the unified name of the
first segment only, ie, HARVARD UNIV.
Institutions in the rankings are numbered from 1 to N, depending on
the ranking option selected, with no repeated ranks for ties (ties
are then ranked alphabetically). Ranking options include citations,
papers, citations per paper, and alphabetic. The citations per
paper measure normalizes to some degree for the institution's
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