Selection Criteria and Methodology of Top 2% Scientists List

Stanford’s Top 2% Scientists List

Stanford’s Top 2% Scientists List is an esteemed ranking that identifies the most cited scholars in their fields. This ranking, derived from Scopus database data, highlights researchers whose work has had a significant impact across various scientific disciplines. This article explains what is the methodology and selection criteria of the Top 2% Scientists List. You can also read this article that explains what is What is the World’s Top 2% Scientists list by Stanford University.

Methodology

The ranking is based on a composite indicator (c-score) calculated from six citation metrics:

• Total citations (NC)
• H-index (H)
• Hm-index (H-index adjusted for the number of authors)
• Citations to single-author papers (NCS)
• Citations to single or first-author papers (NCSF)
• Citations to single, first, or last-author papers (NCSFL)
• The c-score combines these metrics to provide a comprehensive measure of a scientist’s impact, accounting for both the quantity and the quality of their contributions.

Selection Criteria

The list encompasses researchers across 20+ diverse fields. Researchers are categorized into 22 scientific fields and 174 sub-fields based on the standard Science-Metrix classification.

The selection process involves two key steps:

1. Top 100,000 Scientists: Initial Selection of Top 100,000 Scientists
2. 2% Percentile: Subsequent inclusion based on the Top 2% Percentile of their sub-field

This dual approach ensures fair representation across disciplines, as citation patterns vary significantly between fields. For instance, medical and engineering research typically garner higher citation counts compared to social sciences and humanities.

Data and Updates

• Career-long Impact: Metrics cover the entire career of a scientist up to the end of current year-1.
• Recent Year Impact: Metrics focus on citations received during current year-1.
• Latest Version: This latest version is based on the Scopus snapshot as of October 1, current year.
• Transparency and Accessibility: This is a publicly accessible database that includes standardized information on citations, h-index, co-authorship adjusted hm-index, and the c-score. Metrics are available with and without self-citations, and field-specific percentiles are included for all scientists with at least five papers.

For more detailed information, visit data.mendeley.com.