White HD "Author cocitation analysis and Pearson's r" Journal of the American Society for Information Science and Technology 54(13):1250-1259 November 2003,

[Eugene Garfield]

Howard D. White : Howard.Dalby.White at drexel.edu

TITLE    Author cocitation analysis and Pearson's r

AUTHOR   White HD

JOURNAL  JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION
         SCIENCE AND TECHNOLOGY 54 (13): 1250-1259 NOV 2003


 Document type: Article  Language: English  Cited References: 20
 Times Cited: 0

Abstract:
In their article "Requirements for a cocitation similarity measure, with
special reference to Pearson's correlation coefficient," Ahlgren, Jarneving,
and Rousseau fault traditional author cocitation analysis (ACA) for using
Pearson's r as a measure of similarity between authors because it fails two
tests of stability of measurement. The instabilities arise when rs are
recalculated after a first coherent group of authors has been augmented by a
second coherent group with whom the first has little or no cocitation.
However, AJ&R neither cluster nor map their data to demonstrate how
fluctuations in rs will mislead the analyst, and the problem they pose is
remote from both theory and practice in traditional ACA. By entering their
own rs into multidimensional scaling and clustering routines, I show that,
despite rs fluctuations, clusters based on it are much the same for the
combined groups as for the separate groups. The combined groups when mapped
appear as polarized clumps of points in two-dimensional space, confirming
that differences between the groups have become much more important than
differences within the groups-an accurate portrayal of what has happened to
the data. Moreover, r produces clusters and maps very like those based on
other coefficients that AJ&R mention as possible replacements, such as a
cosine similarity measure or a chi square dissimilarity measure. Thus, r
performs well enough for the purposes of ACA. Accordingly, I argue that
qualitative information revealing why authors are cocited is more important
than the cautions proposed in the AJ&R critique. I include notes on topics
such as handling the diagonal in author cocitation matrices, lognormalizing
data, and testing r for significance.

KeyWords Plus:
INTELLECTUAL STRUCTURE, SCIENCE

Addresses:
White HD, Drexel Univ, Coll Informat Sci & Technol, 3152 Chestnut St,
Philadelphia, PA 19104 USA
Drexel Univ, Coll Informat Sci & Technol, Philadelphia, PA 19104 USA

Publisher:
JOHN WILEY & SONS INC, 111 RIVER ST, HOBOKEN, NJ 07030 USA

IDS Number:
730VQ


 Cited Author            Cited Work                Volume      Page   Year
     ID

 AHLGREN P             J AM SOC INF SCI TEC          54       550      2003
 BAYER AE              J AM SOC INFORM SCI           41       444      1990
 BORGATTI SP           UCINET WINDOWS SOFTW                            2002
 BORGATTI SP           WORKSH SUNB 20 INT S                            2000
 DAVISON ML            MULTIDIMENSIONAL SCA                            1983
 EOM SB                J AM SOC INFORM SCI           47       941      1996
 EVERITT B             CLUSTER ANAL                                    1974
 GRIFFITH BC           KEY PAPERS INFORMATI                    R6      1980
 HOPKINS FL            SCIENTOMETRICS                 6        33      1984
 HUBERT L              BRIT J MATH STAT PSY          29       190      1976
 LEYDESDORFF L         INFORMERICS 87 88                      105      1988
 MCCAIN KW             J AM SOC INFORM SCI           41       433      1990
 MCCAIN KW             J AM SOC INFORM SCI           37       111      1986
 MCCAIN KW             J AM SOC INFORM SCI           35       351      1984
 MULLINS NC            THEORIES THEORY GROU                            1973
 WHITE HD              BIBLIOMETRICS SCHOLA                    84      1990
 WHITE HD              J AM SOC INF SCI TEC          54       423      2003
 WHITE HD              J AM SOC INFORM SCI           49       327      1998
 WHITE HD              J AM SOC INFORM SCI           41       430      1990
 WHITE HD              J AM SOC INFORM SCI           32       163      1981


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_______________________________________________________________________
Eugene Garfield, PhD.  email: garfield at codex.cis.upenn.edu
home page: www.eugenegarfield.org
Tel: 215-243-2205 Fax 215-387-1266
President, The Scientist LLC. www.the-scientist.com
Chairman Emeritus, ISI www.isinet.com
Past President, American Society for Information Science and Technology
(ASIS&T)  www.asis.org
_______________________________________________________________________



ISSN:
1532-2882