Darts and sciences

Students intending to study abroad are so used to looking up where universities stand in global league tables that it is easy to forget the rankings are just a decade old - the first was released by Shanghai Jiao Tong University in 2003, creating a huge international buzz.

Since then there has been a profusion of international rankings, mainly published by newspapers and magazines, such as Times Higher Education (THE) and The Guardian in England, and the US News and World Report in America, as well as commercial organisations, such as QS.

International rankings have become so popular that organisations vie against each other to release new lists every year or sub-lists with a tweak - THE's first Asian regional ranking was released on April 10 and QS is planning a Latin American ranking based on "methodology more appropriate to that region".

The main global league tables are timed to coincide with the university applications season - some students wait for the rankings before deciding where to apply.

But do the different rankings, which come out year after year, actually tell students what they want to know? And are they reliable?

Most global rankings "are quite limited in what they measure and thus provide only an incomplete perspective on higher education and on the universities that are ranked," says Philip Altbach, director of the Centre for International Higher Education at Boston College in the US. "The Shanghai rankings are quite clear in what is assessed - only research, research impact, and a few variables related to research, such as prizes awarded to professors and numbers of Nobel winners associated with the institution."