The data above were extracted from the Essential Science
Indicators database of Clarivate. This database, currently
covering the period January 1998 through August 2008, surveys only journal
articles (original research reports and review articles) indexed by Thomson
Reuters. Articles are assigned to a category based on the journals in which
they were published and Clarivate’s journal-to-category field
definition scheme. Both articles tabulated and citation counts to those
articles are for the period indicated. Here our ranking in materials
science is by citations per paper -- among nations that collected 10,000 or
more citations during the period -- to reveal weighted impact. For articles
with multiple authors from different nations, each nation receives full,
not fractional, citation credit. Essential Science Indicators
lists nations ranked in the top 50% for a field over a given period, based
on total citations. In materials science, 78 nations are listed, meaning
156 were surveyed. Thirty-two nations collected at least 10,000 citations
during the period.
This item also appeared in the Times Higher Education magazine,
reprinted with their
permission.