QS World University Rankings by Subject: Methodology
Find out more about the methodology behind the QS World University Rankings by Subject 2022.
Featuring 51 of the most popular subjects with students around the world, the QS World University Rankings by Subject is the most comprehensive ranking of its kind. This year, Harvard University and Massachusetts Institute of Technology (MIT) share the honour of being the top performers globally, ranking as the number one university for 12 subjects each. A further 14 subject rankings tables are topped by British universities.
As well as the rankings for 51 different subjects, the QS World University Rankings by Subject also include five rankings for broad subject areas: Arts & Humanities, Engineering & Technology, Life Sciences & Medicine, Natural Sciences and Social Sciences & Management.
Five components are used to rank universities in the QS World University Rankings by Subject 2022:
· Academic reputation
· Employer reputation
· Research citations per paper
· International Research Network (by broad-faculty area)
The QS World University Rankings by Subject ranks the world’s top universities in individual subject areas, covering 51 subjects. The rankings aim to help prospective students identify the world’s leading schools in their chosen field in response to high demand for subject-level comparisons.
Each of the subject rankings is compiled using four sources. The first two of these are QS’s global surveys of academics and employers, which are used to assess institutions’ international reputation in each subject. The second two indicators assess research impact, based on research citations per paper and h-index in the relevant subject. These are sourced from Elsevier’s Scopus database, the world’s most comprehensive research citations database.
At the broad-faculty area, an additional indicator is used. International Research Network (IRN) shines a light on the sustained international research collaboration of an institution. This was introduced in the 2022 edition of this ranking after broad support from our Global Rankings Advisory Board.
1. Academic reputation
QS’s global survey of academics has been at the heart of the QS World University Rankings® since their inception in 2004. In 2022, the QS World University Rankings by Subject draws on responses from over 130,000 academics worldwide.
Having provided their name, contact details, job title and the institution where they are based, respondents identify the countries, regions and faculty areas they are most familiar with, and up to two narrower subject disciplines in which they have expertise. For each of the (up to two) faculty areas they identify, respondents are asked to list up to 10 domestic and 30 international institutions which they consider to be excellent for research in the given area. They are not able to select their own institution.
For the QS World University Rankings by Subject, the results of the survey are filtered according to the narrow area of expertise identified by respondents. While academics can select up to two narrow areas of expertise, greater emphasis is placed on respondents who have identified only one.
2. Employer reputation
The QS World University Rankings are unique in incorporating employability as a key factor in the evaluation of international universities. In 2022, the QS World University Rankings by Subject draws on nearly 75,000 survey responses from graduate employers worldwide.
The employer reputation survey works on a similar basis to the academic one, but without the channelling for different faculty areas. Employers are asked to identify up to 10 domestic and 30 international institutions they consider excellent for the recruitment of graduates. They are also asked to identify the disciplines from which they prefer to recruit. By examining the intersection of these two questions, we can infer a measure of excellence in a given discipline.
3. Research citations per paper
For the QS World University Rankings by Subject we measure citations per paper, rather than citations per faculty member. This is due to the impracticality of reliably gathering faculty numbers broken down by discipline for each institution.
A minimum publication threshold is set for each subject to avoid potential anomalies stemming from small numbers of highly cited papers. Both the minimum publications threshold and the weighting applied to the citations indicator are adapted in order to best reflect prevalent publication and citation patterns in a given discipline. All citations data is sourced from the Scopus, spanning a five-year period.
A score based on ‘h-index’ has also been incorporated in the QS World University Rankings by Subject. The h-index is a way of measuring both the productivity and impact of the published work of a scientist or scholar. The index is based on the set of the academic’s most cited papers and the number of citations that they have received in other publications.
The h-index can also be applied to the productivity and impact of a group of scientists, such as a department, university or country, as well as a scholarly journal. The index was suggested by Jorge E. Hirsch, a physicist at UCSD, as a tool for determining theoretical physicists’ relative quality, and is sometimes called the Hirsch index or Hirsch number.
5. International Research Network
Introduced this year (2022 edition), the IRN Index reflects the ability of institutions to diversify the geography of their international research network by establishing sustainable research partnerships with other higher education institutions. It also reflects the efficiency of this as we look at the diversity of partner locations against the efforts needed to achieve such a diversity. You can find more details on this indicator here.
As research cultures and publication rates vary significantly across academic disciplines, the QS World University Rankings by Subject applies a different weighting of the above indicators in each subject. For example, in medicine, where publication rates are very high, research citations and the h-index account for 25% of each university’s total score. On the other hand, in areas with much lower publication rates such as history, these research-related indicators only account for 15% of the total ranking score. Meanwhile in subjects such as art and design, where there are too few papers published to be statistically significant, the ranking is based solely on the employer and academic surveys.
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This article was originally published in February 2017 . It was last updated in April 2022