Is measuring the knowledge creation of universities possible?: A review of university rankings

- Variability exists among ranking indexes even in measuring the same criterion.
- Correlations highlight significant differences among university ranking indexes.
- There is a lack of instruments measuring the industry income in almost all indexes.

University ranking indexes are considered very useful benchmarking tools in comparing the performance of universities around the world. Being placed in these prestigious indexes provides a strong advertisement for a university and helps them to attract high-quality students and academicians all over the world. However, there are some important deficiencies of university ranking indexes such as taking into account the whole university as a single unit without differentiating according to different fields of study or research, being limited to some well-known universities, and not considering institutional characteristics such as size or age. This study aims to explore the leading global university rankings to determine the similarities and differences in terms of their ranking criteria, main indicators, modeling choices, and the effects of these on the rankings. Designating the Times Higher Education World Rankings as the base ranking, a comprehensive comparison of the positions of the top universities of the base index with the matched positions of the same universities under other leading indexes including ARWU, QS, Leiden, and URAP is given. Correlations highlight the significant differences among some indexes even in measuring the same criterion such as teaching or research.