CORRESPONDENCE The Top 4 higher education institutions in India and China compared using the Leiden 2022 rankings The Centre for Science and Technology Studies (CWTS) Leiden 2022 rankings (https://www.leidenranking.com/) based on bibliographic data from the Web of Science database of Clarivate Analytics, Philadelphia, PA, USA, which covers twelve sliding four-year time windows, from 2006-09 to 2017-20 was released on June 22, 2022. It now reports the scientific performance of 1318 major higher educational institutions from 69 countries. Institutions are included if they have least 800 Web of Science indexed publications in the period 2017–2020. From India, 49 have made the cut. Unlike other ranking exercises, CWTS offers both size-dependent and size-independent indicators of output and impact. The primary size-dependent indicator is the number of publications P of the university. As the Leiden list also records the number of highly cited publications of the university, which happens to be a size-dependent indicator, a size-independent indicator can be derived from this as the fraction or percentage of the university’s highly cited publications (see below). If normalized with the world average, one can compute a figure q which is a size-independent proxy for the quality of the university’s output. The transparency and rigour of the Leiden Ranking methodology allows us to independently compute composite indicators of performance, as has been done earlier in these pages1,2. Another feature is that the Leiden Ranking enables trend analyses, as it offers over twelve sliding four-year time windows, namely, from 2006–2009, to 2017–2020. The statistics for each time window is presented in a fully consistent way, with citations counted until the end of the first year after the period has ended. For instance, in the case of the period 2006–2009 citations are counted until the end of 2010, while in the case of the period 2017–2020 citations are counted until the end of 2021. 1 We follow the protocol used in our earlier studies1,2 to see how leading higher educational institutions (HEIs) in India have been faring during this period, as compared to the comparators from China. P is the number of bibliometrically fractionalized papers published from each institution during the chosen window (i.e., publications co-authored by multiple institutions are fractionally attributed). The proportion of top 10% publications (PPtop 10%) is arguably the most robust, size-independent proxy or indicator for quality of publications. This is the proportion of the publications of the institution that, compared with other similar publications, belongs to the top 10% most frequently cited. The procedure has a normalizing effect across fields, publication year and document type. The ratio q = PPtop 10%/10, allows one to normalize this proxy, such that a value of 1.00 is the expected global norm. Note that P and q are both primary indicators, one a measure of size of output and the other a proxy for quality of output. P is then a zeroth-order indicator of performance3, and it is possible to combine this to obtain a first-order indicator of performance qP and a second order indicator of performance X = q2P. In this manner, the quantity term (P) and the quality term (q) in the Leiden datasets can be integrated into a single composite term that serves as the best size-dependent proxy for total performance in the research context. In the present exercise, we report only the results for the top four HEIs from India and China using only the fractionalized data. They are: Zhejiang University (29091), Shanghai Jiao Tong University (28703), Tsinghua University (22311), and Huazhong University of Science and Technology (21654), and Indian Institute of Science (4678), Indian Institute of Technology Madras (4600), Indian Institute of Technology Bombay (4447), and Indian Institute of Technology Delhi (4288). The numbers shown in brackets are the fractionalized publications for the latest time window of 2017-2020. Since these are size-dependent, it means that typically a Top 4 institution from China is approximately 5 to 6 times bigger than their counterpart in India. 2 Figure 1 shows the growth of fractionalized output from the Top 4 institutions from China and India over the twelve four-year time windows from 2006-2009 to 2017-2020. The Chinese cohort has been growing much faster than their Indian counterparts. Figure 2 shows the q-P trajectories of the Top 4 institutions from China and India over the twelve four-year time windows from 2006-2009 to 2017-2020. All eight institutions have increased their output but the quality by global standards for India has remained stagnant while that for China has been going up steadily. Indeed, all four from India have been performing below global expectation (q = 1). The overall composite effect of the increase in output and decline in quality is best seen when we see how the X trajectories change over the twelve fouryear time windows from 2006-2020. Figure 3 shows that all our major players, the Indian Institute of Science and the three IITs, are relatively stagnant. The comparators from China have recorded impressive growth during the same period. 1. Prathap, G., Curr. Sci., 2013, 104, 407-408. 2. Prathap, G., Curr. Sci., 2014, 106, 1467-1468. 3. Prathap, G., Curr. Sci., 2010, 98, 995-996. GANGAN PRATHAP A P J Abdul Kalam Technological University, Thiruvananthapuram, Kerala, India 695016. email: gangan_prathap@hotmail.com 3 Figure 1. Growth of fractionalized output from the Top 4 institutions from China and India over the twelve four-year time windows from 2006-2009 to 2017-2020. 4 Figure 2. Growth of fractionalized output from the Top 4 institutions from China and India over the twelve four-year time windows from 2006-2009 to 2017-2020. 5 Figure 3. X trajectories of eight leading HEIs over the twelve four-year time windows from 2006-2009 to 2017-2020. 6