The dissertation provides a normative, descriptive, and prescriptive analysis of the design of societal-preference based health-related quality of life (HRQL) measures. HRQL measures provide the numbers that many researchers and regulators use for quantifying the value of healthcare. The dissertation examines the theoretical foundations of these measures, describes the creation of a new HRQL measure, and characterizes the measurement and policy implications of conventional data-cleaning procedures. Although the focus is on preferences for health, the dissertation is relevant to any work synthesizing the preferences of the lay public, and to surveys where data quality is a concern -- such as many online surveys. For example, much of the dissertation's content could be applied to the design and interpretation of discrete choice experiments eliciting lay preferences for policy options.