Before attempting to rank a laboratory or a university among “the best in the world,” it is necessary to know precisely what “the best” means, by whom it is defined, and on what basis the measurement is made. Without this conception of the nature and consequences of the measurement, the university captains who steer their vessels using bad compasses and ill-calibrated barometers risk sinking in the first storm.
http://www.universityaffairs.ca/opinion/in-my-opinion/academic-rankings-universitys-new-clothes/