Take a look at this graph putting the different rankings for Harvard, MIT, Cambridge, Caltech, Oxford and Stanford together. Red points show the rankings used for the Meta University Ranking (ARWU, QS & THE) and blue points the results of the Leiden 2011/12 and HEEACT 2010 rankings. Although each ranking names another number 1 when the rankings get combined one can see that Harvard and MIT stand out. It illustrates why combining the different rankings makes it much easier to compare schools. Focusing on one single ranking gives you the results of one subjective method.