Highly Cited 
  Researchers 2021
                                ™
              Highly Cited Researchers  have 
              demonstrated significant and broad 
              influence reflected in their publication  
              of multiple highly cited papers over the  
              last decade.
              These highly cited papers rank in the  
              top 1% by citations for a field or fields and 
                                         ™
              publication year in the Web of Science .
              Of the world's population of scientists and 
              social scientists, Highly Cited Researchers 
              are 1 in 1,000.
            The Highly Cited Researchers 
            list is produced each year by 
            the Institute for Scientific                 Overview
                              ™
            Information (ISI)  at 
            Clarivate. ISI has pioneered 
            the organization of the 
            world's research information                 The list of Highly Cited Researchers 2021 from  
            for more than half a century.                               ™ identifies scientists and social scientists  
                                                         Clarivate
            Today it remains committed                   who have demonstrated significant and broad 
            to promoting integrity in                    influence, reflected in the publication of multiple 
            research whilst improving the                papers frequently cited by their peers during the 
            retrieval, interpretation and 
            utility of scientific information.           last decade.
            It maintains the knowledge 
            corpus upon which the Web  
                      ™
            of Science  index and related                Researchers are selected for their           The threshold number of highly cited 
            information and analytical                   exceptional influence and performance        papers for selection differs by field, 
            content and services are built.              in one or more of 21 fields (those used      with Clinical Medicine requiring the 
                                                                                        ™
            It disseminates that knowledge               in Essential Science Indicators  or ESI)     most and Pharmacology/Toxicology 
            externally through events,                   or across several fields.                    the fewest. 
            conferences and publications 
            whilst conducting primary                    6,602 researchers are named Highly 
            research to sustain, extend                  Cited Researchers in 2021 – 3,774 in 
            and improve the knowledge                    specific fields and 2,828 for cross-field 
            base. For more information,                  performance. This is the fourth year 
            please visit clarivate.com.                  that we have identified researchers 
                                                         with cross-field impact.                     6,602
                                  ™
            The Web of Science  
            organizes the world's                        The number of researchers selected           Highly Cited  
            research information to                      in each field is based on the square         Researchers in 2021
            enable academia, corporations,               root of the population of authors listed 
            publishers and governments to                on the field's highly cited papers. 
            accelerate the pace of research.             The number of those with cross-field 
            It is powered by the world's                 influence is determined by finding           A second criterion for selection is a  
            largest publisher-neutral citation           those who have influence equivalent          citation count to highly cited papers  
            index and research intelligence              to those identified in the 21 fields.        that ranks the individual in the top 1%  
            platform. Learn more.                                                                     by total citations in an ESI field for the  
                                                         For the Highly Cited Researchers 2021        period surveyed. 
                                                         analysis, the papers surveyed were the 
                                                         most recent papers available to us – 
                                                         those published and cited during 2010 
                                                         to 2020 and which at the end of 2020 
                                                         ranked in the top 1% by citations for 
                                                         their ESI field and year (the definition 
                                                         of a highly cited paper).
           The Essential Science 
                     ™
           Indicators  database reveals             There is no universally  
           emerging science trends as               agreed concept of what 
           well as influential individuals, 
           institutions, papers, journals and       constitutes extraordinary 
           countries in a field of research. 
           With science trend statistics            research performance
           drawn from more than 12 million 
           articles from over 12,000 global 
           journals, Essential Science 
           Indicators delivers the in-depth 
           coverage needed to effectively           To identify researchers with cross-       a list that satisfies all expectations or 
           analyze and benchmark                    field impact, highly cited paper and      requirements. Moreover, a different 
           research performance, identify           citation counts are normalized through    basis or formula for selection would 
           significant trends, rank top             fractional counting according to the      generate a different – though 
           performers, and evaluate                 thresholds required for each field        likely overlapping – list of names. 
           potential employees and                  (thus, each Clinical Medicine paper       Thus, the absence of a name on 
           collaborators. Learn more.               has a smaller unit fraction, or counts    our list cannot be interpreted as 
                                                    less, than one in Pharmacology/           inferior performance or stature in 
           Incites Benchmarking and                 Toxicology). Citation counts are          comparison to those selected. To 
                    ™
           Analytics  provides objective            treated in a similar manner. If the       understand both the meaning and 
           and reliable indicators needed           sum of the fractional publication         the inevitable limitations of our 
           to make confident, data-driven           counts and the sum of the fractional      analytical approach, a careful reading 
           decisions – to help research             citation counts for a researcher equals   of the methodology is required.
           organizations understand their           1.0 or more, the individual exhibits 
           impact and how they compare              influence equivalent to a researcher 
           to peers across a range of multi-        selected in one or more ESI-defined 
           disciplinary fields. It enables          fields and is therefore selected 
           them to quickly gain the                 as a Highly Cited Researcher for 
           context needed to accurately             exceptional cross-field performance. 
           evaluate funding outcomes, 
           assess collaborations, identify          There is no universally agreed 
           subject matter experts,                  concept of what constitutes 
           benchmark against peers                  extraordinary research performance 
           and more. Learn more.                    and elite status in the sciences and 
                                                    social sciences. Consequently, no 
                                                    quantitative indicators will produce