Times Higher Education (THE) World University Rankings 2015-2016, presented on 1 October, is topped by the California Institute of Technology and University of Oxford, followed by Harvard University in third place. American and British universities dominate the ranking, like in previous years.

THE ranks three Swedish universities among the world's top 100: Karolinska Institutet is placed at 28, Uppsala University at 81 and Lund University at 90. Stockholm University is to be found outside the top 100 list, at 136. The University's position in last year's ranking was 98.

New measurement methods influence the results

Why Stockholm University drops a few positions on the ranking is explained by Gabor Schubert, an analyst at the Stockholm University Library, who believes it is related to the fact that THE has changed method for how to measure citations, which is an important component of the ranking. in addition, THE recently changed supplier, from the Thomson Reuters Web of Science to Elsevier's Scopus, and THE has decided to not include scientific papers with more than 1000 authors from the citation analysis.

According to Gabor Schubert, researchers at Stockholm University were involved in more than 300 of the 649 publications which have been excluded during the preceding year on this basis. For Stockholm University's part, this corresponds to the 3-4 per cent of the university's total publication quantity. “These publications are mostly from physicists, with many citations. I suspect that the university has lost a significant amount of citations because of this”, says Gabor Schubert.

Citations and responses are most important

Main indicators in the Times Higher Education World University Rankings, are a citation indicator and two survey indicators, and together they account for almost 2/3 of the total weight. The weighting is research-oriented and bibliometric indicators account for more than 1/3 of the total weight.

As for the various categories, Stockholm University receives the highest score in the category Citations (which constitute 30 percent of the weighting in the ranking) with 82.5 out of 100.