title: Lotka's law and productivity index of authors in a scientific journal.
abstract: Lotka's law of scientific productivity is a bibliometric example: the number of authors against the number of contributions made by the authors was plotted on a logarithmic scale. The points were closely scattered around a straight line having a slope of -2. The purpose of this study was to apply information technology to real-world data and to quantify the extent of the bibliometric regularity that exists in the literature of dental science. We have analyzed the productivity index of authors (PI) in a scientific journal (Journal of American Dental Association). Details of a total of 4,088 papers published between 1966 and 1995 were extracted electronically from MEDLINE. The total number of authors was 5,589, responsible for 8,569 authorships. Only 0.8% of the authors presented a PI > = 1 (large producers), and 78.1% a PI = 0 (occasional authors). The number of authors publishing N papers was 1/N2.64 of those publishing one paper. The result suggested that repeated publications in the Journal were more difficult than those predicted by Lotka (1/N2).
authors.affiliation: Department of Preventive Dentistry, Faculty of Dentistry, Hiroshima University, Japan. makoto@hiroshima-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Kawamura
authors.forename: C D
authors.initials: CD
authors.lastname: Thomas
authors.forename: A
authors.initials: A
authors.lastname: Tsurumoto
authors.forename: H
authors.initials: H
authors.lastname: Sasahara
authors.forename: Y
authors.initials: Y
authors.lastname: Kawaguchi
mesh_terms: D000465:Algorithms; D000571:American Dental Association; D001319:Authorship; D015706:Bibliometrics; D003813:Dentistry; D004526:Efficiency; D005544:Forecasting; D006801:Humans; D007254:Information Science; D016239:MEDLINE; D015233:Models, Statistical; D010506:Periodicals as Topic; D011643:Publishing; D012044:Regression Analysis; D014481:United States