Why do "Global" University rankings differ so much from "U.S." rankings?

<p>As the title says,
As an example, on "The Top 100 Global Universities" Vanderbilt is ranked at #66, below schools such as Michigan State, University of Minnesota and others that it greatly outranks on U.S. lists like U.S. News.</p>

<p>I know that different lists will have slightly different rankings because of different methods used, but it seems to me as if Global and U.S. rankings have almost nothing in common with each other. Any idea why this is?</p>

<p>Completely different methodologies.</p>

<p>One emphasizes the students, the other faculty accomplishments if you are talking about the SJTU World University Rankings.</p>

<p><a href="http://www.arwu.org/ARWU2009.jsp%5B/url%5D"&gt;http://www.arwu.org/ARWU2009.jsp&lt;/a&gt;&lt;/p>