In a recent analysis of the world's top universities, UC Santa Cruz ranked third in research influence as measured by the number of times its published work is cited by academics.

Published as part of the Times Higher Education World University Rankings 2011-2012, the analysis, conducted by Thomson Reuters, measured overall research influence based on a normalized average number of citations per research paper. The data were aggregated over a six-year period and normalized to reflect variations in citation volume between different subject areas and other factors.

With a citation score of 99.9, UC Santa Cruz ranked behind only Princeton University and the Massachusetts Institute of Technology (both with top scores of 100). Three other universities--the California Institute of Technology, UC Santa Barbara, and Rice University--also had citation scores of 99.9, followed by Stanford and Harvard at 99.8.

The average number of citations per paper, known as citation impact, is a widely used measure of research performance. When researchers publish an article in a scientific journal, they must cite previous papers by other authors that set the stage for their work. Generally, a paper that describes important findings or ideas and influences the work of other researchers receives more citations than less influential papers.

UCSC has been highly ranked in similar surveys in the past that have focused on particular fields of research. Past rankings for the campus, all based on citation impact data, include first among U.S. universities in astronomy and astrophysics (2008), first among U.S. universities in physics (2007), and second worldwide in physical sciences (2001).

UCSC's overall ranking in the THE World University Rankings for 2011-2012 was 110th. It is one of eight UC campuses among the top 200 universities worldwide.