, Volume 90, Issue 2, pp 407–427 | Cite as

A forward diversity index

  • Stephen Carley
  • Alan L. Porter


We introduce an indicator to measure the diffusion of scientific research. Consistent with Stirling’s 3-factor diversity model, the diffusion score captures not only variety and balance, but also disparity among citing article cohorts. We apply it to benchmark article samples from six 1995 Web of Science subject categories (SCs) to trace trends in knowledge diffusion over time since publication. Findings indicate that, for most SCs, diffusion scores steadily increase with time. Mathematics is an outlier. We employ a typology of citation trends among benchmark SCs and correlate this with diffusion scores. We also find that self-cites do not, in most cases, significantly influence diffusion scores.


Knowledge diffusion Integration score Diffusion score Citation patterns Self-citations Subject category behavior 


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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2011

Authors and Affiliations

  1. 1.School of Public PolicyGeorgia Institute of TechnologyAtlantaUSA
  2. 2.Technology Policy and Assessment CenterGeorgia Institute of TechnologyAtlantaUSA
  3. 3.Search Technology Inc.AtlantaUSA

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