concentration of the most-cited papers in the scientific literature analysis of journal ecosystems最常引用的论文集中在科学文献分析生态系统》杂志上.pdf

Concentration of the Most-Cited Papers in the Scientific Literature: Analysis of Journal Ecosystems John P. A. Ioannidis1,2,3* 1 Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece, 2 Biomedical Research Institute, Foundation for Research and Technology-Hellas, Ioannina, Greece, 3 Institute for Clinical Research and Health Policy Studies, Tufts University School of Medicine, Boston, Massachusetts, United States of America Background. A minority of scientific journals publishes the majority of scientific papers and receives the majority of citations. The extent of concentration of the most influential articles is less well known. Methods/Principal Findings. The 100 most- cited papers in the last decade in each of 21 scientific fields were analyzed; fields were considered as ecosystems and their ‘‘species’’ (journal) diversity was evaluated. Only 9% of journals in Journal Citation Reports had published at least one such paper. Among this 9%, half of them had published only one such paper. The number of journals that had published a larger number of most-cited papers decreased exponentially according to a Lotka law. Except for three scientific fields, six journals accounted for 53 to 94 of the 100 most-cited papers in their field. With increasing average number of citations per paper (citation density) in a scientific field, concentration of the most-cited papers in a few journals became even more prominent (p ,0.001). Concentration was unrelated to the number of papers published or number of journals available in a scientific field. Multidisciplinary journals accounted for 24% of all most-cited p