Frequently asked questions

1. What data is held in the Nature Index?

The Nature Index database captures all affiliation information of primary research articles published within 145 natural-science and health-science journals that were selected based on reputation by a panel of active scientists, independently of Springer Nature. It also includes links to the abstracts of those articles. It stores whole article counts (referred to by the metric, Count) and fractional article counts (Share) for each article. Behind the snapshot of data published on the website is a database containing the English names, local language names and acronyms of the parent institutions associated with articles tracked by the Nature Index.

2. Why isn’t my article in the Nature Index?

The Index is updated periodically, so there can be a time lag between when your article is published and when it is added to the Nature Index. Your article may be excluded because it was not a primary research article. Sometimes articles may be missed due to technical difficulties. If you believe this may have happened to a particular article, please contact us.

3. Why isn’t my institution in the Nature Index?

Only institutions with at least one affiliated author on a primary research article published in one of the 145 journals tracked by the index will appear in the Nature Index.

4. Which articles are selected for inclusion in the Nature Index? Are all articles treated equally?

The Nature Index includes only primary research articles published in the 145 selected journals tracked by the Nature Index. For a small number of large physics journals only primary articles identified by the journals as having higher importance, more urgency or more interest for the community are included: notably, articles classified as ‘Highlighted articles’, ‘Editors’ Suggestions’ or ‘Letters’ from Physical Review A, Physical Review B and Physical Review D; and articles classified as ‘Letters’ from Astronomy and Astrophysics.

All articles are treated equally when ordering institutions and countries by Count and Share.

5. How were journals selected for inclusion in the Nature Index?

The journals tracked by the Nature Index were selected based on reputation by panels of actively publishing scientists. The selections were made independently of Springer Nature, and validated by a subsequent survey of global researchers. Panelists and survey respondents were asked to list the journals they would most like to publish in and were asked not to consider the Journal Impact Factor. It is intended that the list of journals amounts to a reasonably consensual upper echelon of journals in the natural sciences and health sciences. It includes both multidisciplinary journals and some of the most highly selective journals within the main disciplines of the natural sciences and health sciences.

The composition and total number of journals included in the Nature Index is reviewed on an ongoing basis. The current list of 145 journals was expanded in June 2023 (see Health sciences added to the Nature Index).

6. Why are articles from only 145 journals included? Why not more?

The selection panels of scientists aimed to ensure there were enough journals to cover many disciplines while maintaining selectivity so that the chosen journals truly reflect the upper tiers of research achievement as judged by peers. The composition and total number of journals included in the Nature Index is reviewed on a regular basis, with the current revised list of 145 journals released in June 2023. The revision and expansion of the Nature Index journals encompasses a number of changes from the original release, including better representation of each of the subjects covered and the inclusion of new journals that were not available when the index was first released. For more information on the selection of Nature Index journals, see Introducing the Index, Revisions to the Nature Index and Health sciences added to the Nature Index.

7. How is article output counted?

Article output is counted in two ways:

1. Count: where a Count of one is assigned to an institution or country/territory if one or more authors of the research article are from that institution or country/territory, regardless of how many co-authors there are from outside that institution or country/territory.
2. Share: an institution’s or country/territory’s Share takes into account the percentage of authors from that institution or country/territory and the number of affiliated institutions per article. For calculation of the Share, all authors are considered to have contributed equally to the article. The maximum combined Share for any article is 1.0.

The ratio of Count to Share gives an indication of the degree to which an institution or country/territory collaborates in its research. Broadly speaking, if the Count is a lot higher than the Share it indicates a high degree of external collaboration and dependency on external resources. If the Count is close in value to the Share it indicates limited collaboration with external researchers and a strong dependency on internal resources.

8. How are the journals and articles categorized by subject?

Research articles are assigned to subjects based on the scientific discipline of the journal in which they are published, with the exception of multidisciplinary journals – Nature, Nature Communications, PNAS, Science and Science Advances. For these journals, subjects are assigned at the article level. Research articles can be assigned to more than one subject. View the complete list of journals in each subject.

9. What is the difference between the ‘Current Index’ and the ‘Research leaders’?

The tables in the ‘Current Index’ represent a dataset for a 12-month rolling window, which is updated monthly. The tables include all institutions and countries/territories with research outputs within the 12-month rolling window. The current date range is clearly indicated. The ‘Research leaders’ are a snapshot of data for one, full calendar year, listing the leading institutions and countries/territories by region/country, sector, and broad subject area. Research Leaders tables from previous years are updated annually to reflect any changes to the database. This means rankings and metrics may differ from the table when first released.

10. What are the limitations of the Nature Index?

The Nature Index tracks a small proportion of the total number of research articles published. There are many factors that determine an institution’s output in the Nature Index. The size of the institution is a major factor, as is the composition of research specialities within the institution. The Nature Index does not attempt to normalize data for such factors. Rather it presents raw data that can contribute to an analysis.

Nature Index recognizes, in line with the San Francisco Declaration on Research Assessment, that multiple factors must be considered when benchmarking research quality and institutional performance, and that outputs from scientific research not only include journal articles, but data, software, intellectual property and highly trained young scientists.

Nature Index metrics alone should not be used to assess institutions or individuals. We encourage users to combine the open source Nature Index data with other information, measures and tools.

11. What journals are in the Nature Index?

The current 12-month window on nature.com/nature-index/ includes data from primary research articles from the following science journals:

12. What institutions are included in the Nature Index?

The Nature Index primarily includes institutions that are central to the administration and/or execution of research, as indicated in author affiliations.These institutions can encompass various organizational structures such as faculties, schools, institutes, departments, or subsidiaries, all of which contribute to the institution’s Count or Share. Institutions can be classified as or associated with the following categories:

Affiliated institutions
• Affiliated joint institutions
• Consortia
• Partner institutions
• Umbrella organisations

For a comprehensive list of included institutions, please refer to the Institutions A-Z section.

Note: Affiliations from funding institutions are generally not credited with a Share, except in circumstances where the funding institution maintains its own research facilities. In such cases, those affiliations will be credited with a Share. Funding institutions lacking their own research facilities are not represented in the institution output tables.

13. How are topics decided?

The Nature Research Intelligence Topics are created from networks of articles that cite each other, or articles that are very similar to each other, and we have over 30,000 topics at the most granular level, grouped into a 4-level hierarchy. On the Nature Index we show topics from the 2nd level of the hierarchy that have enough articles to provide insights on the topic.

Nature Index data for these topics should not be compared with the data used in Nature Index supplements. Supplement topics are defined by using keywords to search for relevant articles in the database and as such represent a different view of a particular field of research.

14. How are regions defined?

15. Which journals are included in the subjects and journal groups?