A Simple Index for the High-Citation Tail of Citation Distribution to Quantify Research Performance in Countries and Institutions
2011

A Simple Index to Quantify Research Performance

publication Evidence: high

Author Information

Author(s): Rodríguez-Navarro Alonso

Primary Institution: Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Madrid, Spain

Hypothesis

The high-citation tail of the citation distribution holds the information about the research level of countries and institutions.

Conclusion

The x-index is a simple and precise indicator for high research performance.

Supporting Evidence

  • The x-index is highly correlated with the number of Nobel Prize achievements.
  • Correlation coefficients for the x-index and Nobel Prize achievements were found to be between 0.81 and 0.88.
  • The study emphasizes the importance of high-citation papers in assessing research performance.

Takeaway

This study created a new way to measure how well countries and institutions do in research by looking at their most cited papers. It shows that some papers are much more important than others.

Methodology

The study proposed the x-index, calculated from the number of national articles in the top 1% and 0.1% of highly cited papers, and validated it against Nobel Prize achievements.

Potential Biases

The exclusion of multinational and review papers may overlook contributions from collaborative research.

Limitations

The x-index cannot be calculated when there are no national articles in the top 1% or 0.1% of highly cited papers.

Statistical Information

P-Value

p<0.001

Statistical Significance

p<0.001

Digital Object Identifier (DOI)

10.1371/journal.pone.0020510

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