Research programme › Science policy


JOURNAL OF DOCUMENTATION; 2004; 60(6):658 - 672

Quantitative deconstruction of citation impact indicators - Waxing field impact but waning journal impact

Authors: Nederhof AJ, Visser MS
Affiliations: Leiden Univ

Abstract:
In two case studies of research units, reference values used to benchmark research performance appeared to show contradictory results: the average citation level in the subfields (FCSm) increased world-wide, while the citation level of the journals (JCSm) decreased, where concomitant changes were expected. Explanations were sought in: a shift in preference of document types; a change in publication preference for subfields; and changes in journal coverage. Publishing in newly covered journals with a low impact had a negative effect on impact ratios. However, the main factor behind the increase in FCSm was the distribution of articles across the five-year block periods that were studied. Publication in lower impact journals produced a lagging JCSm. Actual values of JCSm, FCSm, and citations per publication (CPP) values are not very informative either about research performance, or about the development of impact over time in a certain subfield with block indicators. Normalized citation impact indicators are free from such effects and should be consulted primarily in research performance assessments.

Publication type:
Article in Journal

Journals:
Journal of Documentation
  
Authors (2)
  
MSc M. (Martijn) Visser
Centre for Science and Technology Studies
Researcher. Completing degree in history, Leiden. Currently involved in many research performance projects. From March 1996 at CWTS.
Dr. A.J. (Ton) Nederhof
Senior Researcher. Psychologist, MSc 1978 Leiden University; Ph.D. in Psychology, Leiden, 1981. Lecturer and researcher in Leiden(from 1979), Washington State University (Fulbright Visiting Scholar, 1981-1982) and Auckland (ZWO Visiting Scholar, 1982). Previous work on methods and techniques in ...