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. 2010 Mar;82(3):517-537.
doi: 10.1007/s11192-010-0187-7. Epub 2010 Feb 17.

Self-citations at the meso and individual levels: effects of different calculation methods

Rodrigo Costas, Thed N van Leeuwen, María Bordons

Self-citations at the meso and individual levels: effects of different calculation methods

Rodrigo Costas et al. Scientometrics. 2010 Mar.

Abstract

This paper focuses on the study of self-citations at the meso and micro (individual) levels, on the basis of an analysis of the production (1994-2004) of individual researchers working at the Spanish CSIC in the areas of Biology and Biomedicine and Material Sciences. Two different types of self-citations are described: author self-citations (citations received from the author him/herself) and co-author self-citations (citations received from the researchers' co-authors but without his/her participation). Self-citations do not play a decisive role in the high citation scores of documents either at the individual or at the meso level, which are mainly due to external citations. At micro-level, the percentage of self-citations does not change by professional rank or age, but differences in the relative weight of author and co-author self-citations have been found. The percentage of co-author self-citations tends to decrease with age and professional rank while the percentage of author self-citations shows the opposite trend. Suppressing author self-citations from citation counts to prevent overblown self-citation practices may result in a higher reduction of citation numbers of old scientists and, particularly, of those in the highest categories. Author and co-author self-citations provide valuable information on the scientific communication process, but external citations are the most relevant for evaluative purposes. As a final recommendation, studies considering self-citations at the individual level should make clear whether author or total self-citations are used as these can affect researchers differently.

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Figures

Fig. 1
Fig. 1
Temporal evolution of the percentage of self-citations and external citations by scientific field
Fig. 2
Fig. 2
Percentage of self-citations according to the number of citations
Fig. 3
Fig. 3
Citations, self-citations and external citations by impact factor
Fig. 4
Fig. 4
Mean values of self-citations and external citations by number of authors and centres per document
Fig. 5
Fig. 5
Percentage of self-citations and external citations (left figure) and author and co-author self-citations (right figure) by scientific field
Fig. 6
Fig. 6
Correlations between author and co-author self-citations by scientific field
Fig. 7
Fig. 7
Temporal evolution of the percentage of author and co-author self-citations and external citations by scientific field
Fig. 8
Fig. 8
a Percentage of self-citations and external citations by scientific field and professional category. b Percentage of author and co-author self-citations by scientific field and professional category
Fig. 9
Fig. 9
a Percentage of self-citations and external citations by scientific field and age. b Percentage of author and co-author self-citations by scientific field and age
Fig. 10
Fig. 10
a Percentage of self-citations and external citations by scientific field and scientific class. b Percentage of author and co-author self-citations by scientific field and scientific class
Fig. 11
Fig. 11
Correlations between different CPP scores (individual level). Note: CPP citations per publication, CPP + sc CPP (unsuppressed self-citations), CPP − sc CPP (all self-citations suppressed), CPP − asc CPP (author self-citations suppressed)
Fig. 12
Fig. 12
Inter-ranking comparison of the position of scientists (by quartiles)
See this image and copyright information in PMC

References

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