Patterns of Highly Cited Papers: Social vs. Natural Sciences

1. Do highly cited items in the social sciences have the same patterns as highly cited papers in the natural sciences? 18thNordic Workshop on Bibliometrics and Research Policy, Stockholm, Sweden

2. Background • A few extremely highly cited papers contribute to the most citations, and affect statistical properties of the whole distribution the most  • Characteristics of highly cited papers in the natural sciences • they are authored by many researchers • they are resulted largely by international collaboration • they are mainly published in high-impact journals • they are mainly cited by foreign scientists • the share of self-citations is low • they age less rapidly than other articles (Aksnes, 2003; Aversa, 1985; Oppenheim & Renn, 1978)

3. Research Questions • Are highly cited items in the social sciences authored more researchers than the average items? • Are highly cited items in the social sciences more cited by foreign researchers? • Do highly cited items in the social sciences have lower share of self-citations than the average items? • Do highly cited items in the social sciences age more slowly than the average items? • What are the differences of highly cited items among different document types? • What are the sources, fields,languages, countries, and institutions of the citations of highly cited items in the social sciences ?

4. Methodology How long it takes to be cited? • Field: political science • Publications of: • 2 top-ranking institutions • Department of Political Science at Mannheim University • Institute of Political Science at University of Münster • 33 professors • 1,015 publications; 50 highly cited items • 2003-2007 • sliding citation window: 4 years

5. Data collection • Publication lists from • researchers’ official websites (CV) • institutional repositories • German Social Science Literature Information System (SOLIS) by GESIS • Collected publication lists were sent to professors for verification 60% response rate • Citations of all publications • obtained in March till December 2012 • from the Web of Science in-house database of the Competence Centre for Bibliometricsfor the German Science System (KompetenzzentrumBibliometrie) • author self-citations are included (20%)

6. Definitions • highly cited items • the top 5% cited items of each document type • diachronousauthor self-citation • at least one of the authors of a cited document is the same person as one of the authors of the citing document

7. Total citation counts 2 3 7 • 5% highly cited items contribute nearly 40% citations in general • ISI journal articles is only 16%; Book chapter 71%

8. Average citation rate • Edited Books have the highest average citation rate per item, which is 23.7

9. Are highly cited items authored more researchers than the average items? • authored slightly more researchers in general • except for Journal Articles and Books

10. Are highly cited items more cited by foreign researchers? • not cited by more foreign researchers

11. Do highly cited items have lower share of self-citations than the average items? • lower self-citation rate than other items • except for Edited Book (with the highest number of authors) and Book Chapter

12. Do highly cited items age more slowly than the average items? • aging slightly more slowly than other items

13. What are the sources, fields, languages, countries, and institutions of the citations of highly cited items?

14. Differences between document types • The higher average citation rate, the lower share of citations contributed by highly cited items. • ISI Journal Article: 4.29 (cpp) 16% (% HCI cit) • Book Chapter: 0.28 (cpp) 71% (% HCI cit) • The lower number of authors than all papers, the lower share of self-citations highly cited items have. • Book: 1.00 (app) 4% (% self-cit) • Edited Book: 3.33 (app) 27% (% self-cit)

15. Conclusion • Highly cited items in German political science contribute nearly 40% citations in general • The higher average citation rate, the lower share of citations contributed by highly cited items. • Average citation rate of highly cited items is 6.04 (the rate of all items is 0.74) • Average citation rate of Edited Books is extremely contributed by highly cited items (the biggest difference between HCI and all paper)

16. Conclusion Highly cited items in German political science: • are authored slightly more researchers in general • are not cited by more foreign researchers • not cited internationally • have lower self-citation rate than other items • The lower number of authors than all papers, the lower share of self-citations highly cited items have • age slightly more slowly than other items • are cited mostly by European/German journals and German authors/institutes, within a narrow discipline

17. Thank you very much. chi@forschungsinfo.de