The University of California's census survey of undergraduates, UCUES [University of California Undergraduate Experience Survey], presents an opportunity to measure both disciplinary and institutional differences in students' academic experience. Results from nearly 60,000 responses (38% response rate) from the 2006 administration found greater variance among majors within an institution than between equivalent majors across institutions. Cluster analysis techniques were employed to establish disciplinary patterns, with traditional distinctions between hard and soft sciences generally supported. Reporting practices called into question range from institutional comparisons that ignore academic program mix and discipline to campus performance comparisons that do not recognize pedagogical differences by academic major. More specifically, these results suggest that calls for comparable institutional performance measures, as proposed by the Spellings Commission, must take into consideration disciplinary differences in instruction. (Contains 1 table and 9 figures.) [A version of this paper was presented at the SERU Project Symposium, "Assessing the Undergraduate Experience in the Postmodern University" (Berkeley, CA, April 25, 2007).]