The Nature Index is a database of author affiliations and institutional relationships. The index tracks contributions to research articles published in 82 high-quality natural-science journals, chosen by an independent group of researchers.

The Nature Index provides absolute and fractional counts of article publication at the institutional and national level and, as such, is an indicator of global high-quality research output and collaboration. Data in the Nature Index are updated regularly, with the most recent 12 months made available under a Creative Commons licence at natureindex.com. The database is compiled by Nature Research.

Nature Index metrics

The Nature Index uses Count and Share to track research output. A country/region or an institution is given a Count of 1 for each article that has at least one author from that country/region or institution. This is the case regardless of the number of authors an article has, and it means that the same article can contribute to the Count of multiple countries/regions or institutions.

To glean a country’s, a region’s or an institution’s contribution to an article, and to ensure they are not counted more than once, the Nature Index uses Share, a fractional count that takes into account the share of authorship on each article. The total Share available per article is 1, which is shared among all authors under the assumption that each contributed equally. For instance, an article with 10 authors means that each author receives a Share of 0.1. For authors who are affiliated with more than one institution, the author’s Share is then split equally between each institution. The total Share for an institution is calculated by summing the Share for individual affiliated authors. The process is similar for countries/regions, although complicated by the fact that some institutions have overseas labs that will be counted towards host country/region totals.

natureindex.com natureindex.com users can search for specific institutions or countries and generate their own reports, ordered by Count or Share. Each query will return a profile page that lists the country or institution’s recent outputs, from which it is possible to drill down for more information. Articles can be displayed by journal, and then by article. Research outputs are organized by subject area. The pages list the institution or country/region’s top collaborators, as well as its relationship with other organizations. Users can track an institution’s performance over time, create their own indexes and export table data.

This supplement

Nature Index 2019 Materials science is based on the Nature Index database, covering articles published during the period 1 January 2015 to 31 December 2018, and from 1 January 2012 to 31 December 2018 for country/region level analysis. The data are drawn from a subset of 27 journals in the Nature Index that excludes journals in areas unrelated to materials science. The 27 journals were searched via the Dimensions from Digital Science database to extract materials-science articles, using both keyword and Fields of Research searches.

One table shows leading institutions ranked by their article share (Share) in materials science in 2018. Also listed are each institution's number of materials science articles (Count) in 2018, proportion of Share in materials science relative to total Share (Materials science %) and percentage of internationally collaborative articles (International articles %). The other table shows the top 50 rising institutions ranked by change Share in materials science from 2015 to 2018. Also listed are each institution’s Share in materials science in both years, and percentage change in Share in materials science over the same period.