The ranking compares 1356 higher education institutions worldwide according to a formula that took into account alumni winning Nobel Prizes and Fields Medals (10 percent), staff winning Nobel Prizes and Fields Medals (20 percent), highly cited researchers in 21 broad subject categories (20 percent), articles published in the journals Nature and Science (20 percent), the Science Citation Index and Social Sciences Citation Index (20 percent) and the per capita academic performance (on the indicators above) of an institution (10 percent). The methodology is set out in an academic article by its originators.

The methodology used by the IRI is entirely academic and research oriented.

As the first multi-indicator ranking of global universities, IRI has attracted a great deal of attention from universities, governments and media. A survey on higher education published by The Economist in 2011 commented IRI as “the most widely used annual ranking of the world’s research universities.

One of the factors in the significant influence of IRI is that its methodology is said to look globally sound and transparent. EU Research Headlines reported the IRI ‘s work on 31 December 2009: “The universities were carefully evaluated using several indicators of research performance.

The IRI ranking and its content have been widely cited and applied as a starting point for identifying national strengths and weaknesses as well as facilitating reform and setting new initiatives.