National rankings in materials science

The data above were extracted from the Essential Science Indicators database of Thomson Reuters. This database, currently covering the period January 2000 to April 2010, 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 the Thomson Reuters 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 published 1,000 or more papers during the period to reveal weighted impact.

For articles with multiple authors from different nations, each nation receives full, not fractional, credit. Essential Science Indicators lists nations ranked in the top 50 per cent for a field over a given period based

on total citations. In materials science, 81 nations are listed, meaning 162 were surveyed. Some 47 nations published at least 1,000 papers in this field during the period. The world average in citation impact was 6.49.

For more information, see http://science.thomsonreuters.com/products/esi