Warren E. Miller and Donald E. Stokes' publication in 1963 of a preliminary report on the Survey Research Center's representation study is an important landmark in the development of empirical political theory. That report addressed itself to the crucial theoretical question of the linkage between mass political opinions and governmental policy-making. More specifically, the report found considerable policy agreement between Congressional roll call votes and the attitudes of the individual Congressman's constituency. This policy agreement was then interpreted through several causal paths and the Congressman's perception of his constituency's attitudes was found to be the main path by which the local district ultimately influenced Congressional outputs. The main body of the report dealt with the broad civil rights issue dimension, and, by specifying the perceptual path by which constituency influence is brought to bear, documented the effect of political issues despite the generally low level of political information held at the mass level. Thus, the Congressmen, through their broad cognitive evaluations, were aware of how far they could proceed in determining their civil rights roll call votes on the basis of their own attitudes before risking the displeasure of their constituents. Beyond such major substantive contributions the representation study introduced to political science a variance-apportioning technique similar to that developed by Sewall Wright, in 1921. Through this variance-apportioning technique, the importance of the perceptual link was isolated and evaluated. This study, then, symbolizes the growing recognition in political science of the importance of more sophisticated methodological tools in the process of theory building.