Every year scientists and scholars worldwide publish their findings in academic journals and proceedings producing papers that, according to some estimates, number in excess of 2 million.
With such output, the task of qualifying the value of each piece of work is challenging. Nevertheless, the research community, publishers, academic administrators and others seek such insight, beyond who has the highest salaries, biggest laboratories or office shelves with the most awards.
One strategy is to concentrate on the research papers themselves—specifically, the extent to which they have supported, inspired, or challenged other researchers. Papers meeting this standard earn a clear distinction when other authors explicitly footnote, or cite, the reports in their subsequent work. A paper that other authors have frequently cited has quantifiably proved itself to be significant.
Extending this logic provides a clear avenue: to seek out authors who have consistently produced papers which have, in turn, won peer approval in the form of high citation counts.
This approach is embodied in latest Highly Cited Researcher listing by Clarivate Analytics, which covers the main areas of science and the social sciences and presents researchers who, in their respective fields, have contributed markedly high numbers of top-cited papers over a recent eleven year period, 2004-2014.
The Top 1%
The Highly Cited Researchers website names more than 3,000 researchers with global influence and impact. The list is based on publication and citation figures drawn from Essential Science IndicatorsSM (ESI), a component of the Web of Science™. Among its assorted features and metrics, ESI tracks papers published in the last decade that by citations rank in the top 1% for their respective years of publication in each of 22 main subject fields. These are designated “Highly Cited Papers,” More than 128,000 were identified for the years 2004 to 2014.
Clarivate Analytics identified author names listed on multiple reports within each ESI field. (Each paper is assigned to only one field, depending on the journal in which it appeared, and any paper published in a multidisciplinary journal, such as Science or Nature, is assigned to an ESI field based on algorithmic analysis of the literature predominantly cited by the paper. For example, a Science paper that mostly cites immunology reports would be assigned to the field of Immunology.)
Once the papers have been accurately attributed, the authors are listed within each ESI field according to the number of Highly Cited Papers to their credit. In all, the current listing of Highly Cited Researchers features some 3,100 names.
The fields defined in ESI differ drastically in size. That is, some fields are characterized by greater numbers of journals, in which larger populations of authors publish more papers, and therefore greater quantities of Highly Cited Papers. For example, the field of Clinical Medicine is the largest in ESI, accounting for about 18.2% of the database’s total content. Economics & Business, meanwhile, contributes 1.8% and Microbiology just 1.4%.
The relative size of each ESI field, in terms of the overall number of Highly Cited Papers, was factored into the thresholds that determined how many authors to feature in each field. Varying thresholds are also included in determining how many Highly Cited Papers were required to qualify a given author.
Figure 1 reflects the variance in the size and the corresponding yield of Highly Cited Researchers for the top 10 of the 21 ESI fields, showing the number of authors within each area. Clinical Medicine, as noted earlier, is unmistakably predominant.
Of the 3,265 Highly Cited Researchers (name appearances by field) in the 2016 listings, 1,529 represent US-based institutions—46.8%. The United Kingdom followed at some distance with 324, or 9.9%, with Germany and China also registering strongly. Figure 2 represents a breakdown by nation.
Some institutions proved to be notably prolific in hosting Highly Cited Researchers, as Table 1 indicates. Again, size is a factor, as several of the entities represent large university systems or national research agencies with many component facilities. Harvard University, which boasts the greatest number of names, with 84, is an example, as are the US National Institutes of Health, Stanford University, and the Chinese Academy of Sciences.
Still, some smaller players emerged, such as the Broad Institute of MIT and Harvard in Cambridge, Massachusetts. Caltech (not listed), for example, fielded 13 Highly Cited Researchers, a considerable number for the size of the institution.
Tabulating the most highly cited papers is just one of several possible citation-based measurements for assessing a researcher’s impact. Another approach is to gauge “relative impact” by comparing a citations-per-paper tally against a field-wide baseline. No single approach is ideally comprehensive in scope or outcome, and any scheme will likely exclude accomplished, deserving researchers who do not happen to meet the criteria at hand.
The measure used for identifying Highly Cited Researchers, however, has the advantage of reflecting recent contributions that may come from early- or mid-career researchers, rather than relying on an overall citation count, a measure that tends to favor authors whose work has had many years in which to accumulate citations.
It is a distinction to achieve Highly Cited Researcher status in an ESI field, but many did so in more than one field, demonstrating cross-field impact. More and more, interdisciplinary research is recognized as a locus for breakthrough discoveries, so recognizing researchers with influence spanning several areas is important.
Out of the 3,087 unique Highly Cited Researchers in 2016, 132 were selected in two ESI fields, 20 in three ESI fields, and 2 in four ESI fields. Of special mention are: Michael Graetzel of the École Polytechnique Fédérale de Lausanne, Switzerland, and Sungkyunkwan University, South Korea, who appears in Chemistry, Environmental Sciences and Ecology, Materials Sciences, and in Physics; and Guido Kroemer, Université Paris René Descartes, INSERM U848, and Institut Gustave Roussy, France, who appears in Biochemistry, Immunology, Molecular Biology & Genetics, and in Pharmacology.
Access the website to see all the 3,087 Highly Cited Researchers of 2016 and their areas of expertise.