1. Research Classics and Citation Analysis
Peiling Wang and Jennifer Bownas
School of Information Sciences, University of Tennessee, Knoxville TN 37996
E-mail addresses: {peilingw;jbownas}@utk.edu.
Introduction
Research classics are recognized important works in a field. We
examined 36 classics identified by 8 researchers cited in their research
products. Citing authors' comments about the classics were analyzed
along with citation counts to identify the use contexts. Using the threshold
of 10 citations per year, 11 superstar classics (Table 1) were selected for
in-depth analysis. The nature of each classic was also investigated to
shed light on the success of certain classics.
The purpose of the study is to address the following research questions:
• What do researchers mean when referring to classics in the context of
use? What kinds of classics do they cite?
• What are the characteristics of the 11 superstar classics? What are the
longitudinal citation patterns? the co-citation patterns? the recitation
patterns? the relationships between the citing journals and the journals
that published the superstar classics?
• What is the nature of a superstar classic?
Conclusions
Of the 36 classics identified by researchers, 11 are highly cited and only
one is a Citation Classic. The classics with interdisciplinary appeal or the
works by a classic author tend to be the most highly cited. The 11
superstars show impressive longevity—a continued growth or sustained
counts in citations over 50 years. The co-citation and recitation analyses
are effective tools for identifying unknown classics from known classics
and mapping intellectual and social connections. For works with
pedigrees or sequels, their influences should be measured adequately to
pay appropriate intellectual debts, perhaps by aggregate citation counts.
Results and Discussion
Researchers identified three categories of classics during interviews:
• Classics of a discipline
• Classics of a less active field or smaller community
• Classic authors
A “classic” was often described as a “seminal paper,” “the first attempt,”
“founder,” “pioneer,” "revolutionized", "credible," "the most important one,"
and “well-known.” “Classic" as used by our participants refers to the
quality of the works and their perceived influences in the specific use
contexts rather than citation counts.
Citations to the 36 classics range from five to 2,180. To identify highly
cited classics, we compared two citation measures for ranking classics:
mean and cumulative citations.
Longitudinal patterns: How are the top classics cited over the years?
We plotted the yearly distributions of citations for the 11 superstars. The
few citations for 2004 were excluded in plotting. Figure 1 presents six
selected representative trendlines for the top four classics (the 1st by a
2005 Nobel Prize winner and 3rd by two 2004 Nobel Prize winners), the
6th (the newest), and the 9th (by a 1994 Nobel Prize winner).
Methods
In Wang and White (1999), researchers identified 36 research classics
cited in the references of eight written products (two journal articles, one
book chapter, one dissertation, one Masters thesis, and three proposals).
• Comprehensive Dialog searches of the citations to the 36 classics were
conducted in three ISI Citation Indexes.
• The retrieved records were first imported to a ProCite bibliographic
database to add missing fields and to correct errors.
• Cleansed records were exported to a relational database using
ACCESS for quantitative analyses. The final database includes 11,919
citations: 10,440 citations to the 36 classics plus 1,479 citations to the
two pedigrees.
• Data analysis was facilitated using SQL queries to generate longitudinal
distribution and plot, co-citation, recitation, and citing-cited journal
matrix.
• Citation Classics and HighlyCited.com were searched for additional
information on the classic authors.
How are the classics with a pedigree cited over the years?
Two of the superstar classics each have an earlier edition: Hardy’s 1952
book with 1,648 citations has a first edition (published in 1934) with 1,113
citations; Shephard’s 1970 book with 536 citations has a pedigree
(published in 1953) with 366 citations. Both editions are highly cited and
the sequels have more citations than their pedigrees in most cases.
Recitations of Superstars
If a classic is cited by a citer
in more than one publication
(n >= 2 publications), the
classic has n recitations, or
simply is recited n times.
The results show that 2,063
citers (22%) recited a
superstar in n publications
and 7,307 citers (78%) did
not recite. Thus, the majority
of the superstar citers are
not reciters. The number of
reciters ranges between 69
and 448. To visualize the J-
distribution, we plotted
recitation patterns for the 11
superstar classics. Figure 3
is a plot for the top ranked
classic by Schelling.
Co-citations of Superstars
Two classics are co-cited if they are cited together by a publication. Using
the co-citation data, we determined that the 11 superstars are
interconnected forming a network by at least one co-citation. We identified
a sub-network of seven strongly associated classics forming two clusters
(Figure 2). One cluster includes three classics cited by a faculty
participant (Participant 08) and the other includes four classics cited by
his doctoral advisee (Participant 20). None of the co-citations linking the
two clusters is from either participant, thus it is the co-citation analysis that
reveals the link between the two classics and the two clusters.
Among the reciters, significant image-makers are those who contribute
five or more recitations. The mean number of image-makers for the 11
superstars is 21.5 (SD 3.5; range between 4 and 52). The top reciters for
most of the superstars are a small number of prolific authors.
Citation Classics and Highly Cited Authors
The Schelling work was the only classic that had an autobiographic
reflection in Citation Classics. When his book was selected in 1992, it
had received more than 1,350 citations. Schelling attributed much of the
book’s success to its universal appeal to many disciplines. Only four of
our superstar authors were included in the HighlyCited.com system:
Deaton (the 5th classic), Diewert (the 8th and 11th classics), Kydland,
and Prescott (the 3rd classic).
Analysis of Citing Journals
Distributions of the citations across journals varied. Some citing journals
cited many classics but others cited mainly one classic. We constructed
a matrix of top citing journals and superstars. None of the 7 journal paper
classics was cited most by its own journal. Interestingly, the 11th classic
did not receive a single citation from its journal (Econometrica) in 22
years since its publication. The 230 citations to it were scattered across
94 journals.