Distributional differences of the impact factor in the sciences versus the social sciences: An analysis of the probabilistic structure of the 2005 journal citation reports

This paper examines the probability structure of the 2005 Science Citation Index (SCI) and Social Sciences Citation Index (SSCI) Journal Citation Reports (JCR) by analyzing the Impact Factor distributions of their journals. The distribution of the SCI journals corresponded with a distribution generally modeled by the negative binomial distribution, whereas the SSCI distribution fit the Poisson distribution modeling random, rare events. Both Impact Factor distributions were positively skewed—the SCI much more so than the SSCI—indicating excess variance. One of the causes of this excess variance was that the journals highest in the Impact Factor in both JCRs tended to class in subject categories well funded by the National Institutes of Health. The main reason for the SCI Impact Factor distribution being more skewed than the SSCI one was that review journals defining disciplinary paradigms play a much more important role in the sciences than in the social sciences. © 2008 Wiley Periodicals, Inc.

[1]  P. Seglen,et al.  Education and debate , 1999, The Ethics of Public Health.

[2]  Charles J. Andersen,et al.  A rating of graduate programs , 1970 .

[3]  John Martyn,et al.  An evaluation of British scientific journals , 1968 .

[4]  Stephen J. Bensman,et al.  Scientific and Technical Serials Holdings Optimization in an Inefficient Market: A LSU Serials Redesign Project Exercise , 1998 .

[5]  E. S. Pearson.  Biometrika tables for statisticians , 1967 .

[6]  J. D. Bernal,et al.  The Royal Society Scientific Information Conference , 1948, Nature.

[7]  Lyle V. Jones,et al.  An Assessment of research-doctorate programs in the United States--social and behavioral sciences , 1982 .

[8]  Eugene Garfield,et al.  New factors in the evaluation of scientific literature through citation indexing , 1963 .

[9]  Christian Kay,et al.  The Oxford English Dictionary Online , 2004, Lit. Linguistic Comput..

[10]  J. Coleman.  Introduction to Mathematical Sociology , 1965 .

[11]  N. Diamond,et al.  The Rise of American Research Universities: Elites and Challengers in the Postwar Era , 1997 .

[12]  W. Feller.  On a General Class of "Contagious" Distributions , 1943 .

[13]  R. A. Fisher,et al.  Statistical methods for research workers. Biological monographs and manuals. No. V. , 1950 .

[14]  Stephen J. Bensman.  Probability distributions in library and information science: a historical and practitioner viewpoint , 2000 .

[15]  E. Garfield.  Citation analysis as a tool in journal evaluation. , 1972, Science.

[16]  Cattell Jm,et al.  A FURTHER STATISTICAL STUDY OF AMERICAN MEN OF SCIENCE. , 1910 .

[17]  K S Joseph,et al.  CMAJ's impact factor: room for recalculation. , 1999, CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne.

[18]  M. Greenwood,et al.  An Inquiry into the Nature of Frequency Distributions Representative of Multiple Happenings with Particular Reference to the Occurrence of Multiple Attacks of Disease or of Repeated Accidents , 1920 .

[19]  E. Garfield.  Significant journals of science , 1976, Nature.

[20]  Per Ottar Seglen,et al.  How representative is the journal impact factor , 1992 .

[21]  Student.  An Explanation of Deviations from Poisson's Law in Practice , 1919 .

[22]  Allan M. Cartter,et al.  An Assessment of Quality in Graduate Education , 1966 .

[23]  J. Barnes,et al.  The Complete Works of Aristotle the Revised Oxford Translation , 1984 .

[24]  Stephen J. Bensman.  The impact factor, total citations, and better citation mouse traps: A commentary , 2007 .

[25]  G. Pólya,et al.  Über die Statistik verketteter Vorgänge , 1923 .

[26]  Eugene Garfield,et al.  THE SIGNIFICANT SCIENTIFIC LITERATURE APPEARS IN A SMALL CORE OF JOURNALS , 1996 .

[27]  E. Garfield.  The history and meaning of the journal impact factor. , 2006, JAMA.

[28]  David Adam,et al.  Citation analysis: The counting house , 2002, Nature.

[29]  R. Monastersky.  The number that's devouring science , 2005 .

[30]  J. M. Elliott,et al.  Some methods for the statistical analysis of samples of benthic invertebrates , 1971 .

[31]  B. Maher,et al.  Research-doctorate programs in the United States: continuity and change , 1996 .

[32]  S. Siegel,et al.  Nonparametric Statistics for the Behavioral Sciences , 2022, The SAGE Encyclopedia of Research Design.

[33]  Stephen J. Bensman.  The Structure of the Library Market for Scientific Journals: The Case of Chemistry , 1996 .

[34]  S. Begley.  Science journals artfully try to boost their rankings. , 2006, Wall Street journal.

[35]  W. G. Cochran.  Some Methods for Strengthening the Common χ 2 Tests , 1954 .

[36]  R. Fisher.  Statistical methods for research workers , 1927, Protoplasma.

[37]  Eugene Garfield,et al.  Interview with Eugene Garfield , 2006 .

[38]  R. Lewis,et al.  NEUROGASTROENTEROLOGISTS COMBINE OLD AND NEW RESEARCH APPROACHES , 1996 .

[39]  Stephen J. Bensman.  Garfield and the impact factor , 2007 .

[40]  William H. Beyer,et al.  Handbook of Tables for Probability and Statistics , 1967 .