1. What is ESI?

Essential Science Indicators (ESI) is an in-depth analytical research tool based on the Web of Science Core Collection database.

 

2. ESI Subject Categories

Unlike institutional departments or administrative structures, ESI categorizes research output into the following 22 fields:

• Agricultural Sciences
• Biology & Biochemistry
• Chemistry
• Clinical Medicine
• Computer Science
• Economics & Business
• Engineering
• Environment/Ecology
• Geosciences
• Immunology
• Materials Science
• Mathematics
• Microbiology
• Molecular Biology & Genetics
• Multidisciplinary
• Neuroscience & Behavior
• Pharmacology & Toxicology
• Physics
• Plant & Animal Science
• Psychiatry/Psychology
• Social Sciences, General
• Space Science
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3. ESI Database Overview

• Comprehensive Coverage: Indexes articles and reviews from over 10,000 SCIE/SSCI journals in the Web of Science Core Collection
• Rolling Updates: Provides data from the past decade, updated bimonthly with citation analysis
• Unique Categorization: Each journal is assigned to only one of the 22 ESI subject categories
• Performance Metrics: Delivers research performance statistics and rankings for countries, institutions, and journals across all subjects
• Threshold Values: Establishes entry thresholds for each subject category
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4. ESI Document Types

Included:

• Article
• Review

Excluded:

• Editorial Material
• Biography
• News Item
• Letter
• Bibliography
• Comment
• Book
• Meeting Abstract
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5. Highly Cited Papers & Hot Papers

• Highly Cited Paper: Ranks in the top 1% by citations for its ESI field and publication year
• Hot Paper: Among recent two-year publications, ranks in the top 0.1% by citations over a recent two-month period
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6. Highly Cited Researchers & H-index

• Highly Cited Researchers: Researchers with the most high-impact papers over the past 11 years, recognized globally for exceptional citation influence
• H-index: Measures research impact where a scholar has published h papers each cited at least h times. Higher values indicate greater influence (e.g., an h-index of 20 means 20 papers each with ≥20 citations)

 

7. ESI Thresholds

ESI Thresholds represent the minimum citation counts required over the past decade for:

• Authors and institutions to rank in the top 1% of a subject
• Countries and journals to rank in the top 50%

Example: As of May 2023, institutions needed ≥4,013 total citations to enter the top 1% in Clinical Medicine.

 

8. Institutional Ranking Methodology in ESI Subjects

Institutional rankings within ESI subjects are determined by total citation counts of ESI papers over the past decade. For example, in Clinical Medicine, institutions that have entered the global top 1% are ranked in descending order based on their total citation counts.

Global Significance of ESI Rankings:

• Top 1% Worldwide: Indicates international competitiveness and advanced standing in a discipline
• Top 1‰ Worldwide: Represents international leadership and pioneering status in a field
• Top 0.01% Worldwide: Signifies world-class excellence and cutting-edge research capability

Many leading universities worldwide utilize ESI metrics to evaluate disciplinary strength. In recent years, Chinese educational authorities and institutions have increasingly emphasized ESI indicators, with a growing number of universities establishing "number of ESI global top 1% subjects" as a key institutional development target.