The percentages of shares of world publications of the European Union and its member states, China, and the United States have been represented differently as a result of using different databases. An analytical variant of the Web-of-Science (of Thomson Reuters) enables us to study the dynamics...

Evaluative bibliometrics compare the citation impact of researchers, research groups and institutions with each other across time scales and disciplines. Both factors, discipline and period – have an influence on the citation count which is independent of the quality of the publication....

A proposal is made in this paper for a broadening of perspective in evaluative bibliometrics by complementing the (standard) times cited with a cited reference analysis for a field-specific citation impact measurement. The times cited approach counts the citations of a given publication set. In...

The findings of Bornmann, Leydesdorff, and Wang (2013b) 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...

Bornmann and Leydesdorff (2011) proposed methods based on Web of Science data to identify field-specific excellence in cities where highly cited papers were published more frequently than can be expected. Top performers in output are cities in which authors are located who publish a number of...

For comparisons of citation impacts across fields and over time, bibliometricians normalize the observed citation counts with reference to an expected citation value. Percentile-based approaches have been proposed as a non-parametric alternative to parametric central-tendency statistics....

Given the recent trend in bibliometrics and information science to use increasingly complex statistical methods, it is necessary to have powerful toolboxes to work with data from Web of Science (Thomson Reuters). We developed such a toolbox with four specific commands for the statistical...

As research becomes an ever more globalized activity, there is growing interest in national and international comparisons of standards and quality in different countries and regions. A sign for this trend is the increasing interest in rankings of universities according to their research...

Selection processes are never faultless. We investigate the predictive validity of the manuscript selection process at Angewandte Chemie International Edition (AC-IE), one of the prime chemistry journals worldwide, and conducted a citation analysis for manuscripts that were accepted by the...

A number of bibliometric studies point out that citation counts are a function of many variables besides scientific quality. In this paper our aim is to investigate these factors that usually impact the number of citation counts, using an extensive data set from the field of chemistry. The data...