581 research outputs found
The Leiden Ranking 2011/2012: Data collection, indicators, and interpretation
The Leiden Ranking 2011/2012 is a ranking of universities based on
bibliometric indicators of publication output, citation impact, and scientific
collaboration. The ranking includes 500 major universities from 41 different
countries. This paper provides an extensive discussion of the Leiden Ranking
2011/2012. The ranking is compared with other global university rankings, in
particular the Academic Ranking of World Universities (commonly known as the
Shanghai Ranking) and the Times Higher Education World University Rankings.
Also, a detailed description is offered of the data collection methodology of
the Leiden Ranking 2011/2012 and of the indicators used in the ranking. Various
innovations in the Leiden Ranking 2011/2012 are presented. These innovations
include (1) an indicator based on counting a university's highly cited
publications, (2) indicators based on fractional rather than full counting of
collaborative publications, (3) the possibility of excluding non-English
language publications, and (4) the use of stability intervals. Finally, some
comments are made on the interpretation of the ranking, and a number of
limitations of the ranking are pointed out
Excellence with leadership: the crown indicator of SCImago Institutions Rankings Iber report
Although there are many models for ranking higher education institutions, the SCImago Institutions RankingsĀ methodology stands out for its ability to present quantitative and qualitative indicators of scientific output. Besides Total number of published papers, several indicators are concerned with quality dimensions of published papers, such as International collaboration, Scientific leadership or High quality publications . However, official rankings are provided solely on the basis of one indicator: Output (total number of published papers ). This paper presents a statistical I-distance method that integrates all the indicators into one value, which therefore represent a rank and show which of the input indicators is the most important for the process of ranking. Our results clearly showed that Excellence with LeadershipĀ occupies the most significant spot
How to improve the prediction based on citation impact percentiles for years shortly after the publication date?
The findings of Bornmann, Leydesdorff, and Wang (in press) revealed that the
consideration of journal impact improves the prediction of long-term citation
impact. This paper further explores the possibility of improving citation
impact measurements on the base of a short citation window by the consideration
of journal impact and other variables, such as the number of authors, the
number of cited references, and the number of pages. The dataset contains
475,391 journal papers published in 1980 and indexed in Web of Science (WoS,
Thomson Reuters), and all annual citation counts (from 1980 to 2010) for these
papers. As an indicator of citation impact, we used percentiles of citations
calculated using the approach of Hazen (1914). Our results show that citation
impact measurement can really be improved: If factors generally influencing
citation impact are considered in the statistical analysis, the explained
variance in the long-term citation impact can be much increased. However, this
increase is only visible when using the years shortly after publication but not
when using later years.Comment: Accepted for publication in the Journal of Informetrics. arXiv admin
note: text overlap with arXiv:1306.445
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