How do people arrive at assessments of their own life quality? This investigation begins from the hypothesis that social indicators of perceived well-being will, like other attitudes, reflect tow basic types of influence: affect and cognition. In addition, the indicators were expected to include two other components: unique variance (mainly random measurement error) and correlated measurement error. The extent to which each of these variance components was reflected in assessments of life-as-a-whole from recent national quality of life surveys was estimated by a confirmatory factor analysis model. In addition, a series of models was developed to provide an interpretation of the way the factors of cognition and affect operate along with evaluations of specific life concerns (domains) in the perception of well-being. In the preferred model, it was found that the domain evaluations had no direct impact on life-as-a-whole assessments-the contribution of the domains was indirect by way of their associations with cognition and affect.