In its 2010 survey of American doctoral programs, the National Research Council has placed the Department of Linguistics at the University of Colorado at Boulder in the top quarter of American linguistics programs. Based on an overall measure of excellence that combines factors like publication rates, faculty honors and PhD graduation rates, CU Linguistics was ranked thirteenth out of 52 linguistics programs in the country. CU Linguistics is one of only 2 units in the CU Social Sciences division to rank in the top 20 in their respective disciplines. The NRC operates under the auspices of the National Academy of Sciences, the National Academy of Engineering and the Institute of Medicine. The NRC study of doctoral programs at more than 200 US universities is considered the gold standard of rating systems by the academic community: it offers a much more detailed and comprehensive assessment of PhD programs than do popular ranking systems.