Traditional analyses of agency output are typically performed at the institutional level, characterizing the agency in question as a unitary actor with a singular preference. I test these assumptions using a variety of statistical methods, including a dynamic linear model that estimates ideal points of FCC commissioners for every year, 1975-2000. Voting within the FCC is essentially unidimensional and commissioner preferences are stable over time. Aggregate analyses of the ideal points of individual commissioners suggest that FCC commissioner voting has become profoundly ideological only recently. Future agency research must carefully consider the time period of analysis and previous findings should be reexamined.